From f905440871164adb13e9410934858b761abcd500 Mon Sep 17 00:00:00 2001
From: Duncan Ogilvie <mr.exodia.tpodt@gmail.com>
Date: Tue, 16 Mar 2021 20:01:06 +0100
Subject: [PATCH] Preserve ordering and switch target syntax to use tables

---
 CMakeLists.txt                                |    1 +
 cmake.toml                                    |    8 +-
 src/cmkrlib/cmake.cpp                         |   52 +-
 src/cmkrlib/cmake.hpp                         |    3 +-
 third_party/CMakeLists.txt                    |    5 +
 third_party/ordered-map-1.0.0/LICENSE         |   21 +
 .../include/tsl/ordered_hash.h                | 1628 +++++++++++++++++
 .../include/tsl/ordered_map.h                 |  863 +++++++++
 .../include/tsl/ordered_set.h                 |  718 ++++++++
 9 files changed, 3263 insertions(+), 36 deletions(-)
 create mode 100644 third_party/ordered-map-1.0.0/LICENSE
 create mode 100644 third_party/ordered-map-1.0.0/include/tsl/ordered_hash.h
 create mode 100644 third_party/ordered-map-1.0.0/include/tsl/ordered_map.h
 create mode 100644 third_party/ordered-map-1.0.0/include/tsl/ordered_set.h

diff --git a/CMakeLists.txt b/CMakeLists.txt
index f9aac1c..b67dd89 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -46,6 +46,7 @@ target_link_libraries(cmkrlib PUBLIC
 	toml11
 	ghc_filesystem
 	mpark_variant
+	ordered_map
 )
 
 target_compile_features(cmkrlib PUBLIC
diff --git a/cmake.toml b/cmake.toml
index cd8f185..4afc89a 100644
--- a/cmake.toml
+++ b/cmake.toml
@@ -6,16 +6,14 @@ name = "cmkr"
 version = "0.1.3"
 inject-after = "add_subdirectory(third_party)"
 
-[[target]]
-name = "cmkrlib"
+[target.cmkrlib]
 type = "static"
 sources = ["src/cmkrlib/*.cpp", "src/cmkrlib/*.hpp", "include/*.h"]
 include-directories = ["include"]
 compile-features = ["cxx_std_11"]
-link-libraries = ["toml11", "ghc_filesystem", "mpark_variant"]
+link-libraries = ["toml11", "ghc_filesystem", "mpark_variant", "ordered_map"]
 
-[[target]]
-name = "cmkr"
+[target.cmkr]
 type = "executable"
 sources = ["src/main.cpp"]
 link-libraries = ["cmkrlib"]
diff --git a/src/cmkrlib/cmake.cpp b/src/cmkrlib/cmake.cpp
index 193ff0d..014015b 100644
--- a/src/cmkrlib/cmake.cpp
+++ b/src/cmkrlib/cmake.cpp
@@ -3,14 +3,15 @@
 #include "fs.hpp"
 #include <stdexcept>
 #include <toml.hpp>
+#include <tsl/ordered_map.h>
 
 namespace cmkr {
 namespace cmake {
 
+using TomlBasicValue = toml::basic_value<toml::preserve_comments, tsl::ordered_map, std::vector>;
+
 namespace detail {
-std::vector<std::string> to_string_vec(
-    const std::vector<toml::basic_value<toml::discard_comments, std::unordered_map, std::vector>>
-        &vals) {
+std::vector<std::string> to_string_vec(const std::vector<TomlBasicValue> &vals) {
     std::vector<std::string> temp;
     for (const auto &val : vals)
         temp.push_back(val.as_string());
@@ -22,7 +23,7 @@ CMake::CMake(const std::string &path, bool build) {
     if (!fs::exists(fs::path(path) / "cmake.toml")) {
         throw std::runtime_error("No cmake.toml was found!");
     }
-    const auto toml = toml::parse((fs::path(path) / "cmake.toml").string());
+    const auto toml = toml::parse<toml::preserve_comments, tsl::ordered_map, std::vector>((fs::path(path) / "cmake.toml").string());
     if (build) {
         if (toml.contains("cmake")) {
             const auto &cmake = toml::find(toml, "cmake");
@@ -88,9 +89,7 @@ CMake::CMake(const std::string &path, bool build) {
         }
 
         if (toml.contains("settings")) {
-            using set_map =
-                std::map<std::string, toml::basic_value<toml::discard_comments, std::unordered_map,
-                                                        std::vector>>;
+            using set_map = std::map<std::string, TomlBasicValue>;
             const auto &sets = toml::find<set_map>(toml, "settings");
             for (const auto set : sets) {
                 Setting s;
@@ -123,9 +122,7 @@ CMake::CMake(const std::string &path, bool build) {
         }
 
         if (toml.contains("options")) {
-            using opts_map =
-                std::map<std::string, toml::basic_value<toml::discard_comments, std::unordered_map,
-                                                        std::vector>>;
+            using opts_map = tsl::ordered_map<std::string, TomlBasicValue>;
             const auto &opts = toml::find<opts_map>(toml, "options");
             for (const auto opt : opts) {
                 Option o;
@@ -145,9 +142,7 @@ CMake::CMake(const std::string &path, bool build) {
         }
 
         if (toml.contains("find-package")) {
-            using pkg_map =
-                std::map<std::string, toml::basic_value<toml::discard_comments, std::unordered_map,
-                                                        std::vector>>;
+            using pkg_map = tsl::ordered_map<std::string, TomlBasicValue>;
             const auto &pkgs = toml::find<pkg_map>(toml, "find-package");
             for (const auto &pkg : pkgs) {
                 Package p;
@@ -162,16 +157,16 @@ CMake::CMake(const std::string &path, bool build) {
                         p.required = toml::find(pkg.second, "required").as_boolean();
                     }
                     if (pkg.second.contains("components")) {
-                        p.components =
-                            detail::to_string_vec(toml::find(pkg.second, "components").as_array());
+                        p.components = detail::to_string_vec(toml::find(pkg.second, "components").as_array());
                     }
                 }
                 packages.push_back(p);
             }
         }
 
+        // TODO: refactor to std::vector<Content> instead of this hacky thing?
         if (toml.contains("fetch-content")) {
-            using content_map = std::map<std::string, std::map<std::string, std::string>>;
+            using content_map = tsl::ordered_map<std::string, std::map<std::string, std::string>>;
             contents = toml::find<content_map>(toml, "fetch-content");
         }
 
@@ -180,18 +175,19 @@ CMake::CMake(const std::string &path, bool build) {
         }
 
         if (toml.contains("target")) {
-            const auto &ts = toml::find(toml, "target").as_array();
+            const auto &ts = toml::find(toml, "target").as_table();
 
-            for (const auto &t : ts) {
+            for (const auto &itr : ts) {
+                const auto &t = itr.second;
                 Target target;
-                target.name = toml::find(t, "name").as_string();
+                target.name = itr.first;
                 target.type = toml::find(t, "type").as_string();
 
                 target.sources = detail::to_string_vec(toml::find(t, "sources").as_array());
 
-#define renamed(from, to)                                                                          \
-    if (t.contains(from)) {                                                                        \
-        throw std::runtime_error(from "has been renamed to " to);                                  \
+#define renamed(from, to)                                                                                                                            \
+    if (t.contains(from)) {                                                                                                                          \
+        throw std::runtime_error(from "has been renamed to " to);                                                                                    \
     }
 
                 renamed("include-dirs", "include-directories");
@@ -202,23 +198,19 @@ CMake::CMake(const std::string &path, bool build) {
 #undef renamed
 
                 if (t.contains("include-directories")) {
-                    target.include_directories =
-                        detail::to_string_vec(toml::find(t, "include-directories").as_array());
+                    target.include_directories = detail::to_string_vec(toml::find(t, "include-directories").as_array());
                 }
 
                 if (t.contains("link-libraries")) {
-                    target.link_libraries =
-                        detail::to_string_vec(toml::find(t, "link-libraries").as_array());
+                    target.link_libraries = detail::to_string_vec(toml::find(t, "link-libraries").as_array());
                 }
 
                 if (t.contains("compile-features")) {
-                    target.compile_features =
-                        detail::to_string_vec(toml::find(t, "compile-features").as_array());
+                    target.compile_features = detail::to_string_vec(toml::find(t, "compile-features").as_array());
                 }
 
                 if (t.contains("compile-definitions")) {
-                    target.compile_definitions =
-                        detail::to_string_vec(toml::find(t, "compile-definitions").as_array());
+                    target.compile_definitions = detail::to_string_vec(toml::find(t, "compile-definitions").as_array());
                 }
 
                 if (t.contains("alias")) {
diff --git a/src/cmkrlib/cmake.hpp b/src/cmkrlib/cmake.hpp
index 48d4434..2d91772 100644
--- a/src/cmkrlib/cmake.hpp
+++ b/src/cmkrlib/cmake.hpp
@@ -5,6 +5,7 @@
 #include <string>
 #include <vector>
 #include <mpark/variant.hpp>
+#include <tsl/ordered_map.h>
 
 namespace cmkr {
 namespace cmake {
@@ -76,7 +77,7 @@ struct CMake {
     std::vector<Setting> settings;
     std::vector<Option> options;
     std::vector<Package> packages;
-    std::map<std::string, std::map<std::string, std::string>> contents;
+    tsl::ordered_map<std::string, std::map<std::string, std::string>> contents;
     std::vector<Target> targets;
     std::vector<Test> tests;
     std::vector<Install> installs;
diff --git a/third_party/CMakeLists.txt b/third_party/CMakeLists.txt
index ad7e38b..3afac4c 100644
--- a/third_party/CMakeLists.txt
+++ b/third_party/CMakeLists.txt
@@ -4,6 +4,11 @@
 add_library(ghc_filesystem INTERFACE)
 target_include_directories(ghc_filesystem INTERFACE filesystem-1.5.2/include)
 
+# https://github.com/Tessil/ordered-map (MIT)
+add_library(ordered_map INTERFACE)
+target_include_directories(ordered_map INTERFACE ordered-map-1.0.0/include)
+target_compile_definitions(ordered_map INTERFACE NOMINMAX)
+
 # https://github.com/ToruNiina/toml11 (MIT)
 add_library(toml11 INTERFACE)
 target_include_directories(toml11 INTERFACE toml11-3.6.0)
diff --git a/third_party/ordered-map-1.0.0/LICENSE b/third_party/ordered-map-1.0.0/LICENSE
new file mode 100644
index 0000000..e9c5ae9
--- /dev/null
+++ b/third_party/ordered-map-1.0.0/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2017 Thibaut Goetghebuer-Planchon <tessil@gmx.com>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/third_party/ordered-map-1.0.0/include/tsl/ordered_hash.h b/third_party/ordered-map-1.0.0/include/tsl/ordered_hash.h
new file mode 100644
index 0000000..5fbbfcb
--- /dev/null
+++ b/third_party/ordered-map-1.0.0/include/tsl/ordered_hash.h
@@ -0,0 +1,1628 @@
+/**
+ * MIT License
+ * 
+ * Copyright (c) 2017 Thibaut Goetghebuer-Planchon <tessil@gmx.com>
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#ifndef TSL_ORDERED_HASH_H
+#define TSL_ORDERED_HASH_H
+
+
+#include <algorithm>
+#include <cassert>
+#include <climits>
+#include <cmath>
+#include <cstddef>
+#include <cstdint>
+#include <exception>
+#include <functional>
+#include <iterator>
+#include <limits>
+#include <memory>
+#include <stdexcept>
+#include <tuple>
+#include <type_traits>
+#include <utility>
+#include <vector>
+
+
+/**
+ * Macros for compatibility with GCC 4.8
+ */
+#if (defined(__GNUC__) && (__GNUC__ == 4) && (__GNUC_MINOR__ < 9))
+#    define TSL_OH_NO_CONTAINER_ERASE_CONST_ITERATOR
+#    define TSL_OH_NO_CONTAINER_EMPLACE_CONST_ITERATOR
+#endif
+
+/**
+ * Only activate tsl_oh_assert if TSL_DEBUG is defined. 
+ * This way we avoid the performance hit when NDEBUG is not defined with assert as tsl_oh_assert is used a lot
+ * (people usually compile with "-O3" and not "-O3 -DNDEBUG").
+ */
+#ifdef TSL_DEBUG
+#    define tsl_oh_assert(expr) assert(expr)
+#else
+#    define tsl_oh_assert(expr) (static_cast<void>(0))
+#endif
+
+/**
+ * If exceptions are enabled, throw the exception passed in parameter, otherwise call std::terminate.
+ */
+#if (defined(__cpp_exceptions) || defined(__EXCEPTIONS) || (defined (_MSC_VER) && defined (_CPPUNWIND))) && !defined(TSL_NO_EXCEPTIONS)
+#    define TSL_OH_THROW_OR_TERMINATE(ex, msg) throw ex(msg)
+#else
+#    define TSL_OH_NO_EXCEPTIONS
+#    ifdef NDEBUG
+#        define TSL_OH_THROW_OR_TERMINATE(ex, msg) std::terminate()
+#    else
+#        include <iostream>
+#        define TSL_OH_THROW_OR_TERMINATE(ex, msg) do { std::cerr << msg << std::endl; std::terminate(); } while(0)
+#    endif
+#endif
+
+
+namespace tsl {
+
+namespace detail_ordered_hash {
+    
+template<typename T>
+struct make_void {
+    using type = void;
+};
+
+template<typename T, typename = void>
+struct has_is_transparent: std::false_type {
+};
+
+template<typename T>
+struct has_is_transparent<T, typename make_void<typename T::is_transparent>::type>: std::true_type {
+};
+
+
+template<typename T, typename = void>
+struct is_vector: std::false_type {
+};
+
+template<typename T>
+struct is_vector<T, typename std::enable_if<
+                        std::is_same<T, std::vector<typename T::value_type, typename T::allocator_type>>::value
+                    >::type>: std::true_type {
+};
+
+// Only available in C++17, we need to be compatible with C++11
+template<class T>
+const T& clamp( const T& v, const T& lo, const T& hi) {
+    return std::min(hi, std::max(lo, v));
+}
+
+template<typename T, typename U>
+static T numeric_cast(U value, const char* error_message = "numeric_cast() failed.") {
+    T ret = static_cast<T>(value);
+    if(static_cast<U>(ret) != value) {
+        TSL_OH_THROW_OR_TERMINATE(std::runtime_error, error_message);
+    }
+    
+    const bool is_same_signedness = (std::is_unsigned<T>::value && std::is_unsigned<U>::value) ||
+                                    (std::is_signed<T>::value && std::is_signed<U>::value);
+    if(!is_same_signedness && (ret < T{}) != (value < U{})) {
+        TSL_OH_THROW_OR_TERMINATE(std::runtime_error, error_message);
+    }
+    
+    return ret;
+}
+
+
+/**
+ * Fixed size type used to represent size_type values on serialization. Need to be big enough
+ * to represent a std::size_t on 32 and 64 bits platforms, and must be the same size on both platforms.
+ */
+using slz_size_type = std::uint64_t;
+static_assert(std::numeric_limits<slz_size_type>::max() >= std::numeric_limits<std::size_t>::max(),
+              "slz_size_type must be >= std::size_t");
+
+template<class T, class Deserializer>
+static T deserialize_value(Deserializer& deserializer) {
+    // MSVC < 2017 is not conformant, circumvent the problem by removing the template keyword
+#if defined (_MSC_VER) && _MSC_VER < 1910
+    return deserializer.Deserializer::operator()<T>();
+#else
+    return deserializer.Deserializer::template operator()<T>();
+#endif
+}
+
+
+/**
+ * Each bucket entry stores an index which is the index in m_values corresponding to the bucket's value 
+ * and a hash (which may be truncated to 32 bits depending on IndexType) corresponding to the hash of the value.
+ * 
+ * The size of IndexType limits the size of the hash table to std::numeric_limits<IndexType>::max() - 1 elements (-1 due to 
+ * a reserved value used to mark a bucket as empty).
+ */
+template<class IndexType>
+class bucket_entry {
+    static_assert(std::is_unsigned<IndexType>::value, "IndexType must be an unsigned value.");
+    static_assert(std::numeric_limits<IndexType>::max() <= std::numeric_limits<std::size_t>::max(), 
+                  "std::numeric_limits<IndexType>::max() must be <= std::numeric_limits<std::size_t>::max().");
+    
+public:
+    using index_type = IndexType;
+    using truncated_hash_type = typename std::conditional<std::numeric_limits<IndexType>::max() <= 
+                                                          std::numeric_limits<std::uint_least32_t>::max(),
+                                                              std::uint_least32_t, 
+                                                              std::size_t>::type;
+    
+    bucket_entry() noexcept: m_index(EMPTY_MARKER_INDEX), m_hash(0) {
+    }
+    
+    bool empty() const noexcept {
+        return m_index == EMPTY_MARKER_INDEX;
+    }
+    
+    void clear() noexcept {
+        m_index = EMPTY_MARKER_INDEX;
+    }
+    
+    index_type index() const noexcept {
+        tsl_oh_assert(!empty());
+        return m_index;
+    }
+    
+    index_type& index_ref() noexcept {
+        tsl_oh_assert(!empty());
+        return m_index;
+    }
+    
+    void set_index(index_type index) noexcept {
+        tsl_oh_assert(index <= max_size());
+        
+        m_index = index;
+    }
+    
+    truncated_hash_type truncated_hash() const noexcept {
+        tsl_oh_assert(!empty());
+        return m_hash;
+    }
+    
+    truncated_hash_type& truncated_hash_ref() noexcept {
+        tsl_oh_assert(!empty());
+        return m_hash;
+    }
+    
+    void set_hash(std::size_t hash) noexcept {
+        m_hash = truncate_hash(hash);
+    }
+    
+    template<class Serializer>
+    void serialize(Serializer& serializer) const {
+        const slz_size_type index = m_index;
+        serializer(index);
+        
+        const slz_size_type hash = m_hash;
+        serializer(hash);
+    }
+    
+    template<class Deserializer>
+    static bucket_entry deserialize(Deserializer& deserializer) {
+        const slz_size_type index = deserialize_value<slz_size_type>(deserializer);
+        const slz_size_type hash = deserialize_value<slz_size_type>(deserializer);
+        
+        bucket_entry bentry;
+        bentry.m_index = numeric_cast<index_type>(index, "Deserialized index is too big.");
+        bentry.m_hash = numeric_cast<truncated_hash_type>(hash, "Deserialized hash is too big.");
+        
+        return bentry;
+    }
+    
+    
+    
+    static truncated_hash_type truncate_hash(std::size_t hash) noexcept {
+        return truncated_hash_type(hash);
+    }
+    
+    static std::size_t max_size() noexcept {
+        return static_cast<std::size_t>(std::numeric_limits<index_type>::max()) - NB_RESERVED_INDEXES;
+    }
+    
+private:
+    static const index_type EMPTY_MARKER_INDEX = std::numeric_limits<index_type>::max();
+    static const std::size_t NB_RESERVED_INDEXES = 1;
+    
+    index_type m_index;
+    truncated_hash_type m_hash;
+};
+
+
+
+/**
+ * Internal common class used by ordered_map and ordered_set.
+ * 
+ * ValueType is what will be stored by ordered_hash (usually std::pair<Key, T> for map and Key for set).
+ * 
+ * KeySelect should be a FunctionObject which takes a ValueType in parameter and return a reference to the key.
+ * 
+ * ValueSelect should be a FunctionObject which takes a ValueType in parameter and return a reference to the value. 
+ * ValueSelect should be void if there is no value (in set for example).
+ * 
+ * ValueTypeContainer is the container which will be used to store ValueType values. 
+ * Usually a std::deque<ValueType, Allocator> or std::vector<ValueType, Allocator>.
+ * 
+ * 
+ * 
+ * The ordered_hash structure is a hash table which preserves the order of insertion of the elements.
+ * To do so, it stores the values in the ValueTypeContainer (m_values) using emplace_back at each
+ * insertion of a new element. Another structure (m_buckets of type std::vector<bucket_entry>) will 
+ * serve as buckets array for the hash table part. Each bucket stores an index which corresponds to 
+ * the index in m_values where the bucket's value is and the (truncated) hash of this value. An index
+ * is used instead of a pointer to the value to reduce the size of each bucket entry.
+ * 
+ * To resolve collisions in the buckets array, the structures use robin hood linear probing with 
+ * backward shift deletion.
+ */
+template<class ValueType,
+         class KeySelect,
+         class ValueSelect,
+         class Hash,
+         class KeyEqual,
+         class Allocator,
+         class ValueTypeContainer,
+         class IndexType>
+class ordered_hash: private Hash, private KeyEqual {
+private:
+    template<typename U>
+    using has_mapped_type = typename std::integral_constant<bool, !std::is_same<U, void>::value>;
+    
+    static_assert(std::is_same<typename ValueTypeContainer::value_type, ValueType>::value, 
+                  "ValueTypeContainer::value_type != ValueType. "
+                  "Check that the ValueTypeContainer has 'Key' as type for a set or 'std::pair<Key, T>' as type for a map.");
+    
+    static_assert(std::is_same<typename ValueTypeContainer::allocator_type, Allocator>::value, 
+                  "ValueTypeContainer::allocator_type != Allocator. "
+                  "Check that the allocator for ValueTypeContainer is the same as Allocator.");
+    
+    static_assert(std::is_same<typename Allocator::value_type, ValueType>::value, 
+                  "Allocator::value_type != ValueType. "
+                  "Check that the allocator has 'Key' as type for a set or 'std::pair<Key, T>' as type for a map.");
+    
+    
+public:
+    template<bool IsConst>
+    class ordered_iterator;
+    
+    using key_type = typename KeySelect::key_type;
+    using value_type = ValueType;
+    using size_type = std::size_t;
+    using difference_type = std::ptrdiff_t;
+    using hasher = Hash;
+    using key_equal = KeyEqual;
+    using allocator_type = Allocator;
+    using reference = value_type&;
+    using const_reference = const value_type&;
+    using pointer = value_type*;
+    using const_pointer = const value_type*;
+    using iterator = ordered_iterator<false>;
+    using const_iterator = ordered_iterator<true>;
+    using reverse_iterator = std::reverse_iterator<iterator>;
+    using const_reverse_iterator = std::reverse_iterator<const_iterator>;
+    
+    using values_container_type = ValueTypeContainer;
+    
+public:
+    template<bool IsConst>
+    class ordered_iterator {
+        friend class ordered_hash;
+        
+    private:
+        using iterator = typename std::conditional<IsConst, 
+                                                    typename values_container_type::const_iterator, 
+                                                    typename values_container_type::iterator>::type;
+    
+        
+        ordered_iterator(iterator it) noexcept: m_iterator(it) {
+        }
+        
+    public:
+        using iterator_category = std::random_access_iterator_tag;
+        using value_type = const typename ordered_hash::value_type;
+        using difference_type = typename iterator::difference_type;
+        using reference = value_type&;
+        using pointer = value_type*;
+        
+        
+        ordered_iterator() noexcept {
+        }
+        
+        // Copy constructor from iterator to const_iterator.
+        template<bool TIsConst = IsConst, typename std::enable_if<TIsConst>::type* = nullptr>
+        ordered_iterator(const ordered_iterator<!TIsConst>& other) noexcept: m_iterator(other.m_iterator) {
+        }
+
+        ordered_iterator(const ordered_iterator& other) = default;
+        ordered_iterator(ordered_iterator&& other) = default;
+        ordered_iterator& operator=(const ordered_iterator& other) = default;
+        ordered_iterator& operator=(ordered_iterator&& other) = default;
+
+        const typename ordered_hash::key_type& key() const {
+            return KeySelect()(*m_iterator);
+        }
+
+        template<class U = ValueSelect, typename std::enable_if<has_mapped_type<U>::value && IsConst>::type* = nullptr>
+        const typename U::value_type& value() const {
+            return U()(*m_iterator);
+        }
+
+        template<class U = ValueSelect, typename std::enable_if<has_mapped_type<U>::value && !IsConst>::type* = nullptr>
+        typename U::value_type& value() {
+            return U()(*m_iterator);
+        }
+        
+        reference operator*() const { return *m_iterator; }
+        pointer operator->() const { return m_iterator.operator->(); }
+        
+        ordered_iterator& operator++() { ++m_iterator; return *this; }
+        ordered_iterator& operator--() { --m_iterator; return *this; }
+        
+        ordered_iterator operator++(int) { ordered_iterator tmp(*this); ++(*this); return tmp; }
+        ordered_iterator operator--(int) { ordered_iterator tmp(*this); --(*this); return tmp; }
+        
+        reference operator[](difference_type n) const { return m_iterator[n]; }
+        
+        ordered_iterator& operator+=(difference_type n) { m_iterator += n; return *this; }
+        ordered_iterator& operator-=(difference_type n) { m_iterator -= n; return *this; }
+        
+        ordered_iterator operator+(difference_type n) { ordered_iterator tmp(*this); tmp += n; return tmp; }
+        ordered_iterator operator-(difference_type n) { ordered_iterator tmp(*this); tmp -= n; return tmp; }
+        
+        friend bool operator==(const ordered_iterator& lhs, const ordered_iterator& rhs) { 
+            return lhs.m_iterator == rhs.m_iterator; 
+        }
+        
+        friend bool operator!=(const ordered_iterator& lhs, const ordered_iterator& rhs) { 
+            return lhs.m_iterator != rhs.m_iterator; 
+        }
+        
+        friend bool operator<(const ordered_iterator& lhs, const ordered_iterator& rhs) { 
+            return lhs.m_iterator < rhs.m_iterator; 
+        }
+        
+        friend bool operator>(const ordered_iterator& lhs, const ordered_iterator& rhs) { 
+            return lhs.m_iterator > rhs.m_iterator; 
+        }
+        
+        friend bool operator<=(const ordered_iterator& lhs, const ordered_iterator& rhs) { 
+            return lhs.m_iterator <= rhs.m_iterator; 
+        }
+        
+        friend bool operator>=(const ordered_iterator& lhs, const ordered_iterator& rhs) { 
+            return lhs.m_iterator >= rhs.m_iterator; 
+        }
+
+        friend ordered_iterator operator+(difference_type n, const ordered_iterator& it) { 
+            return n + it.m_iterator;
+        }
+
+        friend difference_type operator-(const ordered_iterator& lhs, const ordered_iterator& rhs) { 
+            return lhs.m_iterator - rhs.m_iterator; 
+        }
+
+    private:
+        iterator m_iterator;
+    };
+    
+    
+private:
+    using bucket_entry = tsl::detail_ordered_hash::bucket_entry<IndexType>;
+                                         
+    using buckets_container_allocator = typename 
+                            std::allocator_traits<allocator_type>::template rebind_alloc<bucket_entry>; 
+                            
+    using buckets_container_type = std::vector<bucket_entry, buckets_container_allocator>;
+    
+    
+    using truncated_hash_type = typename bucket_entry::truncated_hash_type;
+    using index_type = typename bucket_entry::index_type;
+    
+public:
+    ordered_hash(size_type bucket_count, 
+                 const Hash& hash,
+                 const KeyEqual& equal,
+                 const Allocator& alloc,
+                 float max_load_factor): Hash(hash),
+                                         KeyEqual(equal), 
+                                         m_buckets_data(alloc), 
+                                         m_buckets(static_empty_bucket_ptr()), 
+                                         m_hash_mask(0),
+                                         m_values(alloc), 
+                                         m_grow_on_next_insert(false)
+    {
+        if(bucket_count > max_bucket_count()) {
+            TSL_OH_THROW_OR_TERMINATE(std::length_error, "The map exceeds its maximum size.");
+        }
+        
+        if(bucket_count > 0) {
+            bucket_count = round_up_to_power_of_two(bucket_count);
+            
+            m_buckets_data.resize(bucket_count);
+            m_buckets = m_buckets_data.data(),
+            m_hash_mask = bucket_count - 1;
+        }
+        
+        this->max_load_factor(max_load_factor);
+    }
+    
+    ordered_hash(const ordered_hash& other): Hash(other),
+                                             KeyEqual(other),
+                                             m_buckets_data(other.m_buckets_data),
+                                             m_buckets(m_buckets_data.empty()?static_empty_bucket_ptr():
+                                                                              m_buckets_data.data()),
+                                             m_hash_mask(other.m_hash_mask),
+                                             m_values(other.m_values),
+                                             m_load_threshold(other.m_load_threshold),
+                                             m_max_load_factor(other.m_max_load_factor),
+                                             m_grow_on_next_insert(other.m_grow_on_next_insert)
+    {
+    }
+    
+    ordered_hash(ordered_hash&& other) noexcept(std::is_nothrow_move_constructible<Hash>::value &&
+                                                std::is_nothrow_move_constructible<KeyEqual>::value &&
+                                                std::is_nothrow_move_constructible<buckets_container_type>::value &&
+                                                std::is_nothrow_move_constructible<values_container_type>::value)
+                                          : Hash(std::move(static_cast<Hash&>(other))),
+                                            KeyEqual(std::move(static_cast<KeyEqual&>(other))),
+                                            m_buckets_data(std::move(other.m_buckets_data)),
+                                            m_buckets(m_buckets_data.empty()?static_empty_bucket_ptr():
+                                                                             m_buckets_data.data()),
+                                            m_hash_mask(other.m_hash_mask),
+                                            m_values(std::move(other.m_values)),
+                                            m_load_threshold(other.m_load_threshold),
+                                            m_max_load_factor(other.m_max_load_factor),
+                                            m_grow_on_next_insert(other.m_grow_on_next_insert)
+    {
+        other.m_buckets_data.clear();
+        other.m_buckets = static_empty_bucket_ptr();
+        other.m_hash_mask = 0;
+        other.m_values.clear();
+        other.m_load_threshold = 0;
+        other.m_grow_on_next_insert = false;
+    }
+    
+    ordered_hash& operator=(const ordered_hash& other) {
+        if(&other != this) {
+            Hash::operator=(other);
+            KeyEqual::operator=(other);
+            
+            m_buckets_data = other.m_buckets_data;
+            m_buckets = m_buckets_data.empty()?static_empty_bucket_ptr():
+                                               m_buckets_data.data();
+                                                        
+            m_hash_mask = other.m_hash_mask;
+            m_values = other.m_values;
+            m_load_threshold = other.m_load_threshold;
+            m_max_load_factor = other.m_max_load_factor;
+            m_grow_on_next_insert = other.m_grow_on_next_insert;
+        }
+        
+        return *this;
+    }
+    
+    ordered_hash& operator=(ordered_hash&& other) {
+        other.swap(*this);
+        other.clear();
+        
+        return *this;
+    }
+    
+    allocator_type get_allocator() const {
+        return m_values.get_allocator();
+    }
+    
+    
+    /*
+     * Iterators
+     */
+    iterator begin() noexcept {
+        return iterator(m_values.begin());
+    }
+    
+    const_iterator begin() const noexcept {
+        return cbegin();
+    }
+    
+    const_iterator cbegin() const noexcept {
+        return const_iterator(m_values.cbegin());
+    }
+    
+    iterator end() noexcept {
+        return iterator(m_values.end());
+    }
+    
+    const_iterator end() const noexcept {
+        return cend();
+    }
+    
+    const_iterator cend() const noexcept {
+        return const_iterator(m_values.cend());
+    }  
+    
+    
+    reverse_iterator rbegin() noexcept {
+        return reverse_iterator(m_values.end());
+    }
+    
+    const_reverse_iterator rbegin() const noexcept {
+        return rcbegin();
+    }
+    
+    const_reverse_iterator rcbegin() const noexcept {
+        return const_reverse_iterator(m_values.cend());
+    }
+    
+    reverse_iterator rend() noexcept {
+        return reverse_iterator(m_values.begin());
+    }
+    
+    const_reverse_iterator rend() const noexcept {
+        return rcend();
+    }
+    
+    const_reverse_iterator rcend() const noexcept {
+        return const_reverse_iterator(m_values.cbegin());
+    }  
+    
+    
+    /*
+     * Capacity
+     */
+    bool empty() const noexcept {
+        return m_values.empty();
+    }
+    
+    size_type size() const noexcept {
+        return m_values.size();
+    }
+    
+    size_type max_size() const noexcept {
+        return std::min(bucket_entry::max_size(), m_values.max_size());
+    }
+    
+
+    /*
+     * Modifiers
+     */
+    void clear() noexcept {
+        for(auto& bucket: m_buckets_data) {
+            bucket.clear();
+        }
+        
+        m_values.clear();
+        m_grow_on_next_insert = false;
+    }
+    
+    template<typename P>
+    std::pair<iterator, bool> insert(P&& value) {
+        return insert_impl(KeySelect()(value), std::forward<P>(value));
+    }
+    
+    template<typename P>
+    iterator insert_hint(const_iterator hint, P&& value) { 
+        if(hint != cend() && compare_keys(KeySelect()(*hint), KeySelect()(value))) { 
+            return mutable_iterator(hint); 
+        }
+        
+        return insert(std::forward<P>(value)).first; 
+    }
+    
+    template<class InputIt>
+    void insert(InputIt first, InputIt last) {
+        if(std::is_base_of<std::forward_iterator_tag, 
+                           typename std::iterator_traits<InputIt>::iterator_category>::value) 
+        {
+            const auto nb_elements_insert = std::distance(first, last);
+            const size_type nb_free_buckets = m_load_threshold - size();
+            tsl_oh_assert(m_load_threshold >= size());
+            
+            if(nb_elements_insert > 0 && nb_free_buckets < size_type(nb_elements_insert)) {
+                reserve(size() + size_type(nb_elements_insert));
+            }
+        }
+        
+        for(; first != last; ++first) {
+            insert(*first);
+        }
+    }
+    
+    
+    
+    template<class K, class M>
+    std::pair<iterator, bool> insert_or_assign(K&& key, M&& value) {
+        auto it = try_emplace(std::forward<K>(key), std::forward<M>(value));
+        if(!it.second) {
+            it.first.value() = std::forward<M>(value);
+        }
+        
+        return it;
+    }
+    
+    template<class K, class M>
+    iterator insert_or_assign(const_iterator hint, K&& key, M&& obj) {
+        if(hint != cend() && compare_keys(KeySelect()(*hint), key)) { 
+            auto it = mutable_iterator(hint); 
+            it.value() = std::forward<M>(obj);
+            
+            return it;
+        }
+        
+        return insert_or_assign(std::forward<K>(key), std::forward<M>(obj)).first;
+    }
+    
+    
+    
+    template<class... Args>
+    std::pair<iterator, bool> emplace(Args&&... args) {
+        return insert(value_type(std::forward<Args>(args)...));
+    }
+    
+    template<class... Args>
+    iterator emplace_hint(const_iterator hint, Args&&... args) { 
+        return insert_hint(hint, value_type(std::forward<Args>(args)...));
+    }
+    
+    
+    
+    template<class K, class... Args>
+    std::pair<iterator, bool> try_emplace(K&& key, Args&&... value_args) {
+        return insert_impl(key, std::piecewise_construct, 
+                                std::forward_as_tuple(std::forward<K>(key)), 
+                                std::forward_as_tuple(std::forward<Args>(value_args)...));     
+    }
+    
+    template<class K, class... Args>
+    iterator try_emplace_hint(const_iterator hint, K&& key, Args&&... args) {
+        if(hint != cend() && compare_keys(KeySelect()(*hint), key)) { 
+            return mutable_iterator(hint); 
+        }
+        
+        return try_emplace(std::forward<K>(key), std::forward<Args>(args)...).first;
+    }
+    
+    
+    
+    /**
+     * Here to avoid `template<class K> size_type erase(const K& key)` being used when
+     * we use an `iterator` instead of a `const_iterator`.
+     */
+    iterator erase(iterator pos) {
+        return erase(const_iterator(pos));
+    }
+    
+    iterator erase(const_iterator pos) {
+        tsl_oh_assert(pos != cend());
+        
+        const std::size_t index_erase = iterator_to_index(pos);
+        
+        auto it_bucket = find_key(pos.key(), hash_key(pos.key()));
+        tsl_oh_assert(it_bucket != m_buckets_data.end());
+        
+        erase_value_from_bucket(it_bucket);
+        
+        /*
+         * One element was removed from m_values, due to the left shift the next element 
+         * is now at the position of the previous element (or end if none).
+         */
+        return begin() + index_erase;
+    }
+
+    iterator erase(const_iterator first, const_iterator last) {
+        if(first == last) {
+            return mutable_iterator(first);
+        }
+        
+        tsl_oh_assert(std::distance(first, last) > 0);
+        const std::size_t start_index = iterator_to_index(first);
+        const std::size_t nb_values = std::size_t(std::distance(first, last));
+        const std::size_t end_index = start_index + nb_values;
+        
+        // Delete all values
+#ifdef TSL_OH_NO_CONTAINER_ERASE_CONST_ITERATOR     
+        auto next_it = m_values.erase(mutable_iterator(first).m_iterator, mutable_iterator(last).m_iterator);   
+#else
+        auto next_it = m_values.erase(first.m_iterator, last.m_iterator);
+#endif
+        
+        /*
+         * Mark the buckets corresponding to the values as empty and do a backward shift.
+         * 
+         * Also, the erase operation on m_values has shifted all the values on the right of last.m_iterator.
+         * Adapt the indexes for these values.
+         */
+        std::size_t ibucket = 0;
+        while(ibucket < m_buckets_data.size()) {
+            if(m_buckets[ibucket].empty()) {
+                ibucket++;
+            }
+            else if(m_buckets[ibucket].index() >= start_index && m_buckets[ibucket].index() < end_index) {
+                m_buckets[ibucket].clear();
+                backward_shift(ibucket);
+                // Don't increment ibucket, backward_shift may have replaced current bucket.
+            }
+            else if(m_buckets[ibucket].index() >= end_index) {
+                m_buckets[ibucket].set_index(index_type(m_buckets[ibucket].index() - nb_values));
+                ibucket++;
+            }
+            else {
+                ibucket++;
+            }
+        }
+        
+        return iterator(next_it);
+    }
+    
+
+    template<class K>
+    size_type erase(const K& key) {
+        return erase(key, hash_key(key));
+    }
+    
+    template<class K>
+    size_type erase(const K& key, std::size_t hash) {
+        return erase_impl(key, hash);
+    }
+    
+    void swap(ordered_hash& other) {
+        using std::swap;
+        
+        swap(static_cast<Hash&>(*this), static_cast<Hash&>(other));
+        swap(static_cast<KeyEqual&>(*this), static_cast<KeyEqual&>(other));
+        swap(m_buckets_data, other.m_buckets_data);
+        swap(m_buckets, other.m_buckets);
+        swap(m_hash_mask, other.m_hash_mask);
+        swap(m_values, other.m_values);
+        swap(m_load_threshold, other.m_load_threshold);
+        swap(m_max_load_factor, other.m_max_load_factor);
+        swap(m_grow_on_next_insert, other.m_grow_on_next_insert);
+    }
+    
+        
+    
+
+    /*
+     * Lookup
+     */    
+    template<class K, class U = ValueSelect, typename std::enable_if<has_mapped_type<U>::value>::type* = nullptr>
+    typename U::value_type& at(const K& key) {
+        return at(key, hash_key(key));
+    }
+    
+    template<class K, class U = ValueSelect, typename std::enable_if<has_mapped_type<U>::value>::type* = nullptr>
+    typename U::value_type& at(const K& key, std::size_t hash) {
+        return const_cast<typename U::value_type&>(static_cast<const ordered_hash*>(this)->at(key, hash));
+    }
+    
+    template<class K, class U = ValueSelect, typename std::enable_if<has_mapped_type<U>::value>::type* = nullptr>
+    const typename U::value_type& at(const K& key) const {
+        return at(key, hash_key(key));
+    }
+    
+    template<class K, class U = ValueSelect, typename std::enable_if<has_mapped_type<U>::value>::type* = nullptr>
+    const typename U::value_type& at(const K& key, std::size_t hash) const {
+        auto it = find(key, hash);
+        if(it != end()) {
+            return it.value();
+        }
+        else {
+            TSL_OH_THROW_OR_TERMINATE(std::out_of_range, "Couldn't find the key.");
+        }
+    }
+    
+    
+    template<class K, class U = ValueSelect, typename std::enable_if<has_mapped_type<U>::value>::type* = nullptr>
+    typename U::value_type& operator[](K&& key) {
+        return try_emplace(std::forward<K>(key)).first.value();
+    }
+    
+    
+    template<class K>
+    size_type count(const K& key) const {
+        return count(key, hash_key(key));
+    }
+    
+    template<class K>
+    size_type count(const K& key, std::size_t hash) const {
+        if(find(key, hash) == cend()) {
+            return 0;
+        }
+        else {
+            return 1;
+        }
+    }
+    
+    template<class K>
+    iterator find(const K& key) {
+        return find(key, hash_key(key));
+    }
+    
+    template<class K>
+    iterator find(const K& key, std::size_t hash) {
+        auto it_bucket = find_key(key, hash);
+        return (it_bucket != m_buckets_data.end())?iterator(m_values.begin() + it_bucket->index()):end();
+    }
+    
+    template<class K>
+    const_iterator find(const K& key) const {
+        return find(key, hash_key(key));
+    }
+    
+    template<class K>
+    const_iterator find(const K& key, std::size_t hash) const {
+        auto it_bucket = find_key(key, hash);
+        return (it_bucket != m_buckets_data.cend())?const_iterator(m_values.begin() + it_bucket->index()):end();
+    }
+    
+
+    template<class K>
+    bool contains(const K& key) const {
+        return contains(key, hash_key(key));
+    }
+    
+    template<class K>
+    bool contains(const K& key, std::size_t hash) const {
+        return find(key, hash) != cend();
+    }
+    
+    
+    template<class K>
+    std::pair<iterator, iterator> equal_range(const K& key) {
+        return equal_range(key, hash_key(key));
+    }
+    
+    template<class K>
+    std::pair<iterator, iterator> equal_range(const K& key, std::size_t hash) {
+        iterator it = find(key, hash);
+        return std::make_pair(it, (it == end())?it:std::next(it));
+    }
+    
+    template<class K>
+    std::pair<const_iterator, const_iterator> equal_range(const K& key) const {
+        return equal_range(key, hash_key(key));
+    }
+    
+    template<class K>
+    std::pair<const_iterator, const_iterator> equal_range(const K& key, std::size_t hash) const {
+        const_iterator it = find(key, hash);
+        return std::make_pair(it, (it == cend())?it:std::next(it));
+    }    
+    
+    
+    /*
+     * Bucket interface 
+     */
+    size_type bucket_count() const {
+        return m_buckets_data.size(); 
+    }
+    
+    size_type max_bucket_count() const {
+        return m_buckets_data.max_size();
+    }    
+    
+    /*
+     *  Hash policy 
+     */
+    float load_factor() const {
+        if(bucket_count() == 0) {
+            return 0;
+        }
+        
+        return float(size())/float(bucket_count());
+    }
+    
+    float max_load_factor() const {
+        return m_max_load_factor;
+    }
+    
+    void max_load_factor(float ml) {
+        m_max_load_factor = clamp(ml, float(MAX_LOAD_FACTOR__MINIMUM), 
+                                      float(MAX_LOAD_FACTOR__MAXIMUM));
+
+        m_max_load_factor = ml;
+        m_load_threshold = size_type(float(bucket_count())*m_max_load_factor);
+    }
+    
+    void rehash(size_type count) {
+        count = std::max(count, size_type(std::ceil(float(size())/max_load_factor())));
+        rehash_impl(count);
+    }
+    
+    void reserve(size_type count) {
+        reserve_space_for_values(count);
+        
+        count = size_type(std::ceil(float(count)/max_load_factor()));
+        rehash(count);
+    }
+    
+    
+    /*
+     * Observers
+     */
+    hasher hash_function() const {
+        return static_cast<const Hash&>(*this);
+    }
+    
+    key_equal key_eq() const {
+        return static_cast<const KeyEqual&>(*this);
+    }
+
+    
+    /*
+     * Other
+     */
+    iterator mutable_iterator(const_iterator pos) {
+        return iterator(m_values.begin() + iterator_to_index(pos));
+    }
+    
+    iterator nth(size_type index) {
+        tsl_oh_assert(index <= size());
+        return iterator(m_values.begin() + index);
+    }
+    
+    const_iterator nth(size_type index) const {
+        tsl_oh_assert(index <= size());
+        return const_iterator(m_values.cbegin() + index);
+    }
+    
+    const_reference front() const {
+        tsl_oh_assert(!empty());
+        return m_values.front();
+    }
+    
+    const_reference back() const {
+        tsl_oh_assert(!empty());
+        return m_values.back();
+    }
+    
+    const values_container_type& values_container() const noexcept {
+        return m_values;
+    }
+    
+    template<class U = values_container_type, typename std::enable_if<is_vector<U>::value>::type* = nullptr>    
+    const typename values_container_type::value_type* data() const noexcept {
+        return m_values.data();
+    }
+    
+    template<class U = values_container_type, typename std::enable_if<is_vector<U>::value>::type* = nullptr>    
+    size_type capacity() const noexcept {
+        return m_values.capacity();
+    }
+    
+    void shrink_to_fit() {
+        m_values.shrink_to_fit();
+    }
+    
+    
+    template<typename P>
+    std::pair<iterator, bool> insert_at_position(const_iterator pos, P&& value) {
+        return insert_at_position_impl(pos.m_iterator, KeySelect()(value), std::forward<P>(value));
+    }
+    
+    template<class... Args>
+    std::pair<iterator, bool> emplace_at_position(const_iterator pos, Args&&... args) {
+        return insert_at_position(pos, value_type(std::forward<Args>(args)...));
+    }
+    
+    template<class K, class... Args>
+    std::pair<iterator, bool> try_emplace_at_position(const_iterator pos, K&& key, Args&&... value_args) {
+        return insert_at_position_impl(pos.m_iterator, key, 
+                                       std::piecewise_construct, 
+                                       std::forward_as_tuple(std::forward<K>(key)), 
+                                       std::forward_as_tuple(std::forward<Args>(value_args)...));
+    }
+    
+
+    void pop_back() {
+        tsl_oh_assert(!empty());
+        erase(std::prev(end()));
+    }
+    
+    
+    /**
+     * Here to avoid `template<class K> size_type unordered_erase(const K& key)` being used when
+     * we use a iterator instead of a const_iterator.
+     */    
+    iterator unordered_erase(iterator pos) {
+        return unordered_erase(const_iterator(pos));
+    }
+    
+    iterator unordered_erase(const_iterator pos) {
+        const std::size_t index_erase = iterator_to_index(pos);
+        unordered_erase(pos.key());
+        
+        /*
+         * One element was deleted, index_erase now points to the next element as the elements after
+         * the deleted value were shifted to the left in m_values (will be end() if we deleted the last element).
+         */
+        return begin() + index_erase;
+    }
+    
+    template<class K>
+    size_type unordered_erase(const K& key) {
+        return unordered_erase(key, hash_key(key));
+    }
+    
+    template<class K>
+    size_type unordered_erase(const K& key, std::size_t hash) {
+        auto it_bucket_key = find_key(key, hash);
+        if(it_bucket_key == m_buckets_data.end()) {
+            return 0;
+        }
+        
+        /**
+         * If we are not erasing the last element in m_values, we swap 
+         * the element we are erasing with the last element. We then would 
+         * just have to do a pop_back() in m_values.
+         */
+        if(!compare_keys(key, KeySelect()(back()))) {
+            auto it_bucket_last_elem = find_key(KeySelect()(back()), hash_key(KeySelect()(back())));
+            tsl_oh_assert(it_bucket_last_elem != m_buckets_data.end());
+            tsl_oh_assert(it_bucket_last_elem->index() == m_values.size() - 1);
+            
+            using std::swap;
+            swap(m_values[it_bucket_key->index()], m_values[it_bucket_last_elem->index()]);
+            swap(it_bucket_key->index_ref(), it_bucket_last_elem->index_ref());
+        }
+        
+        erase_value_from_bucket(it_bucket_key);
+        
+        return 1;
+    }
+    
+    template<class Serializer>
+    void serialize(Serializer& serializer) const {
+        serialize_impl(serializer);
+    }
+    
+    template<class Deserializer>
+    void deserialize(Deserializer& deserializer, bool hash_compatible) {
+        deserialize_impl(deserializer, hash_compatible);
+    }
+    
+    friend bool operator==(const ordered_hash& lhs, const ordered_hash& rhs) {
+        return lhs.m_values == rhs.m_values;
+    }
+    
+    friend bool operator!=(const ordered_hash& lhs, const ordered_hash& rhs) {
+        return lhs.m_values != rhs.m_values;
+    }
+    
+    friend bool operator<(const ordered_hash& lhs, const ordered_hash& rhs) {
+        return lhs.m_values < rhs.m_values;
+    }
+    
+    friend bool operator<=(const ordered_hash& lhs, const ordered_hash& rhs) {
+        return lhs.m_values <= rhs.m_values;
+    }
+    
+    friend bool operator>(const ordered_hash& lhs, const ordered_hash& rhs) {
+        return lhs.m_values > rhs.m_values;
+    }
+    
+    friend bool operator>=(const ordered_hash& lhs, const ordered_hash& rhs) {
+        return lhs.m_values >= rhs.m_values;
+    }
+    
+    
+private:
+    template<class K>
+    std::size_t hash_key(const K& key) const {
+        return Hash::operator()(key);
+    }
+    
+    template<class K1, class K2>
+    bool compare_keys(const K1& key1, const K2& key2) const {
+        return KeyEqual::operator()(key1, key2);
+    }
+    
+    template<class K>
+    typename buckets_container_type::iterator find_key(const K& key, std::size_t hash) {
+        auto it = static_cast<const ordered_hash*>(this)->find_key(key, hash);
+        return m_buckets_data.begin() + std::distance(m_buckets_data.cbegin(), it);
+    }
+    
+    /**
+     * Return bucket which has the key 'key' or m_buckets_data.end() if none.
+     * 
+     * From the bucket_for_hash, search for the value until we either find an empty bucket
+     * or a bucket which has a value with a distance from its ideal bucket longer
+     * than the probe length for the value we are looking for.
+     */
+    template<class K>
+    typename buckets_container_type::const_iterator find_key(const K& key, std::size_t hash) const {
+        for(std::size_t ibucket = bucket_for_hash(hash), dist_from_ideal_bucket = 0; ; 
+            ibucket = next_bucket(ibucket), dist_from_ideal_bucket++) 
+        {
+            if(m_buckets[ibucket].empty()) {
+                return m_buckets_data.end();
+            }
+            else if(m_buckets[ibucket].truncated_hash() == bucket_entry::truncate_hash(hash) && 
+                    compare_keys(key, KeySelect()(m_values[m_buckets[ibucket].index()]))) 
+            {
+                return m_buckets_data.begin() + ibucket;
+            }
+            else if(dist_from_ideal_bucket > distance_from_ideal_bucket(ibucket)) {
+                return m_buckets_data.end();
+            }
+        }
+    }
+    
+    void rehash_impl(size_type bucket_count) {
+        tsl_oh_assert(bucket_count >= size_type(std::ceil(float(size())/max_load_factor())));
+        
+        if(bucket_count > max_bucket_count()) {
+            TSL_OH_THROW_OR_TERMINATE(std::length_error, "The map exceeds its maximum size.");
+        }
+        
+        if(bucket_count > 0) {
+            bucket_count = round_up_to_power_of_two(bucket_count);
+        }
+        
+        if(bucket_count == this->bucket_count()) {
+            return;
+        }
+        
+        
+        buckets_container_type old_buckets(bucket_count);
+        m_buckets_data.swap(old_buckets);
+        m_buckets = m_buckets_data.empty()?static_empty_bucket_ptr():
+                                           m_buckets_data.data();
+        // Everything should be noexcept from here.
+        
+        m_hash_mask = (bucket_count > 0)?(bucket_count - 1):0;
+        this->max_load_factor(m_max_load_factor);
+        m_grow_on_next_insert = false;
+        
+        
+        
+        for(const bucket_entry& old_bucket: old_buckets) {
+            if(old_bucket.empty()) {
+                continue;
+            }
+            
+            truncated_hash_type insert_hash = old_bucket.truncated_hash();
+            index_type insert_index = old_bucket.index();
+            
+            for(std::size_t ibucket = bucket_for_hash(insert_hash), dist_from_ideal_bucket = 0; ; 
+                ibucket = next_bucket(ibucket), dist_from_ideal_bucket++) 
+            {
+                if(m_buckets[ibucket].empty()) {
+                    m_buckets[ibucket].set_index(insert_index);
+                    m_buckets[ibucket].set_hash(insert_hash);
+                    break;
+                }
+                
+                const std::size_t distance = distance_from_ideal_bucket(ibucket);
+                if(dist_from_ideal_bucket > distance) {
+                    std::swap(insert_index, m_buckets[ibucket].index_ref());
+                    std::swap(insert_hash, m_buckets[ibucket].truncated_hash_ref());
+                    dist_from_ideal_bucket = distance;
+                }
+            }
+        }
+    }
+    
+    template<class T = values_container_type, typename std::enable_if<is_vector<T>::value>::type* = nullptr>
+    void reserve_space_for_values(size_type count) {
+        m_values.reserve(count);
+    }
+    
+    template<class T = values_container_type, typename std::enable_if<!is_vector<T>::value>::type* = nullptr>
+    void reserve_space_for_values(size_type /*count*/) {
+    }
+    
+    /**
+     * Swap the empty bucket with the values on its right until we cross another empty bucket
+     * or if the other bucket has a distance_from_ideal_bucket == 0.
+     */
+    void backward_shift(std::size_t empty_ibucket) noexcept {
+        tsl_oh_assert(m_buckets[empty_ibucket].empty());
+        
+        std::size_t previous_ibucket = empty_ibucket;
+        for(std::size_t current_ibucket = next_bucket(previous_ibucket); 
+            !m_buckets[current_ibucket].empty() && distance_from_ideal_bucket(current_ibucket) > 0;
+            previous_ibucket = current_ibucket, current_ibucket = next_bucket(current_ibucket)) 
+        {
+            std::swap(m_buckets[current_ibucket], m_buckets[previous_ibucket]);
+        }
+    }
+    
+    void erase_value_from_bucket(typename buckets_container_type::iterator it_bucket) {
+        tsl_oh_assert(it_bucket != m_buckets_data.end() && !it_bucket->empty());
+        
+        m_values.erase(m_values.begin() + it_bucket->index());
+        
+        /*
+         * m_values.erase shifted all the values on the right of the erased value, 
+         * shift the indexes by -1 in the buckets array for these values.
+         */
+        if(it_bucket->index() != m_values.size()) {
+            shift_indexes_in_buckets(it_bucket->index(), -1);
+        }        
+        
+        // Mark the bucket as empty and do a backward shift of the values on the right
+        it_bucket->clear();
+        backward_shift(std::size_t(std::distance(m_buckets_data.begin(), it_bucket)));
+    }
+    
+    /**
+     * Go through each value from [from_ivalue, m_values.size()) in m_values and for each
+     * bucket corresponding to the value, shift the index by delta.
+     * 
+     * delta must be equal to 1 or -1.
+     */
+    void shift_indexes_in_buckets(index_type from_ivalue, int delta) noexcept  {
+        tsl_oh_assert(delta == 1 || delta == -1);
+        
+        for(std::size_t ivalue = from_ivalue; ivalue < m_values.size(); ivalue++) {
+            // All the values in m_values have been shifted by delta. Find the bucket corresponding 
+            // to the value m_values[ivalue]
+            const index_type old_index = static_cast<index_type>(ivalue - delta);
+            
+            std::size_t ibucket = bucket_for_hash(hash_key(KeySelect()(m_values[ivalue])));
+            while(m_buckets[ibucket].index() != old_index) {
+                ibucket = next_bucket(ibucket);
+            }
+            
+            m_buckets[ibucket].set_index(index_type(ivalue));
+        }
+    }
+    
+    template<class K>
+    size_type erase_impl(const K& key, std::size_t hash) {
+        auto it_bucket = find_key(key, hash);
+        if(it_bucket != m_buckets_data.end()) {
+            erase_value_from_bucket(it_bucket);
+            
+            return 1;
+        }
+        else {
+            return 0;
+        }
+    }
+    
+    /**
+     * Insert the element at the end.
+     */
+    template<class K, class... Args>
+    std::pair<iterator, bool> insert_impl(const K& key, Args&&... value_type_args) {
+        const std::size_t hash = hash_key(key);
+        
+        std::size_t ibucket = bucket_for_hash(hash); 
+        std::size_t dist_from_ideal_bucket = 0;
+        
+        while(!m_buckets[ibucket].empty() && dist_from_ideal_bucket <= distance_from_ideal_bucket(ibucket)) {
+            if(m_buckets[ibucket].truncated_hash() == bucket_entry::truncate_hash(hash) && 
+               compare_keys(key, KeySelect()(m_values[m_buckets[ibucket].index()]))) 
+            {
+                return std::make_pair(begin() + m_buckets[ibucket].index(), false);
+            }
+            
+            ibucket = next_bucket(ibucket);
+            dist_from_ideal_bucket++;
+        }
+        
+        if(size() >= max_size()) {
+            TSL_OH_THROW_OR_TERMINATE(std::length_error, "We reached the maximum size for the hash table.");
+        }
+        
+        
+        if(grow_on_high_load()) {
+            ibucket = bucket_for_hash(hash);
+            dist_from_ideal_bucket = 0;
+        }
+        
+                
+        m_values.emplace_back(std::forward<Args>(value_type_args)...);
+        insert_index(ibucket, dist_from_ideal_bucket, 
+                     index_type(m_values.size() - 1), bucket_entry::truncate_hash(hash));
+        
+        
+        return std::make_pair(std::prev(end()), true);
+    }
+    
+    /**
+     * Insert the element before insert_position.
+     */
+    template<class K, class... Args>
+    std::pair<iterator, bool> insert_at_position_impl(typename values_container_type::const_iterator insert_position,
+                                                      const K& key, Args&&... value_type_args) 
+    {
+        const std::size_t hash = hash_key(key);
+        
+        std::size_t ibucket = bucket_for_hash(hash); 
+        std::size_t dist_from_ideal_bucket = 0;
+        
+        while(!m_buckets[ibucket].empty() && dist_from_ideal_bucket <= distance_from_ideal_bucket(ibucket)) {
+            if(m_buckets[ibucket].truncated_hash() == bucket_entry::truncate_hash(hash) && 
+               compare_keys(key, KeySelect()(m_values[m_buckets[ibucket].index()]))) 
+            {
+                return std::make_pair(begin() + m_buckets[ibucket].index(), false);
+            }
+            
+            ibucket = next_bucket(ibucket);
+            dist_from_ideal_bucket++;
+        }
+        
+        if(size() >= max_size()) {
+            TSL_OH_THROW_OR_TERMINATE(std::length_error, "We reached the maximum size for the hash table.");
+        }
+        
+        
+        if(grow_on_high_load()) {
+            ibucket = bucket_for_hash(hash);
+            dist_from_ideal_bucket = 0;
+        }
+        
+        
+        const index_type index_insert_position = index_type(std::distance(m_values.cbegin(), insert_position));
+        
+#ifdef TSL_OH_NO_CONTAINER_EMPLACE_CONST_ITERATOR
+        m_values.emplace(m_values.begin() + std::distance(m_values.cbegin(), insert_position), std::forward<Args>(value_type_args)...);
+#else        
+        m_values.emplace(insert_position, std::forward<Args>(value_type_args)...);
+#endif        
+
+        insert_index(ibucket, dist_from_ideal_bucket, 
+                     index_insert_position, bucket_entry::truncate_hash(hash));
+        
+        /*
+         * The insertion didn't happend at the end of the m_values container, 
+         * we need to shift the indexes in m_buckets_data.
+         */
+        if(index_insert_position != m_values.size() - 1) {
+            shift_indexes_in_buckets(index_insert_position + 1, 1);
+        }
+        
+        return std::make_pair(iterator(m_values.begin() + index_insert_position), true);
+    }
+    
+    void insert_index(std::size_t ibucket, std::size_t dist_from_ideal_bucket, 
+                      index_type index_insert, truncated_hash_type hash_insert) noexcept
+    {
+        while(!m_buckets[ibucket].empty()) {
+            const std::size_t distance = distance_from_ideal_bucket(ibucket);
+            if(dist_from_ideal_bucket > distance) {
+                std::swap(index_insert, m_buckets[ibucket].index_ref());
+                std::swap(hash_insert, m_buckets[ibucket].truncated_hash_ref());
+                
+                dist_from_ideal_bucket = distance;
+            }
+
+            
+            ibucket = next_bucket(ibucket);
+            dist_from_ideal_bucket++;
+            
+            
+            if(dist_from_ideal_bucket > REHASH_ON_HIGH_NB_PROBES__NPROBES && !m_grow_on_next_insert &&
+               load_factor() >= REHASH_ON_HIGH_NB_PROBES__MIN_LOAD_FACTOR)
+            {
+                // We don't want to grow the map now as we need this method to be noexcept.
+                // Do it on next insert.
+                m_grow_on_next_insert = true;
+            }
+        }
+        
+        
+        m_buckets[ibucket].set_index(index_insert);
+        m_buckets[ibucket].set_hash(hash_insert); 
+    }
+    
+    std::size_t distance_from_ideal_bucket(std::size_t ibucket) const noexcept {
+        const std::size_t ideal_bucket = bucket_for_hash(m_buckets[ibucket].truncated_hash());
+        
+        if(ibucket >= ideal_bucket) {
+            return ibucket - ideal_bucket;
+        }
+        // If the bucket is smaller than the ideal bucket for the value, there was a wrapping at the end of the 
+        // bucket array due to the modulo.
+        else {
+            return (bucket_count() + ibucket) - ideal_bucket;
+        }
+    }
+    
+    std::size_t next_bucket(std::size_t index) const noexcept {
+        tsl_oh_assert(index < m_buckets_data.size());
+        
+        index++;
+        return (index < m_buckets_data.size())?index:0;
+    }
+    
+    std::size_t bucket_for_hash(std::size_t hash) const noexcept {
+        return hash & m_hash_mask;
+    }    
+    
+    std::size_t iterator_to_index(const_iterator it) const noexcept {
+        const auto dist = std::distance(cbegin(), it);
+        tsl_oh_assert(dist >= 0);
+        
+        return std::size_t(dist);
+    }
+    
+    /**
+     * Return true if the map has been rehashed.
+     */
+    bool grow_on_high_load() {
+        if(m_grow_on_next_insert || size() >= m_load_threshold) {
+            rehash_impl(std::max(size_type(1), bucket_count() * 2));
+            m_grow_on_next_insert = false;
+            
+            return true;
+        }
+        else {
+            return false;
+        }
+    }
+    
+    template<class Serializer>
+    void serialize_impl(Serializer& serializer) const {
+        const slz_size_type version = SERIALIZATION_PROTOCOL_VERSION;
+        serializer(version);
+        
+        const slz_size_type nb_elements = m_values.size();
+        serializer(nb_elements);
+        
+        const slz_size_type bucket_count = m_buckets_data.size();
+        serializer(bucket_count);
+        
+        const float max_load_factor = m_max_load_factor;
+        serializer(max_load_factor);
+        
+        
+        for(const value_type& value: m_values) {
+            serializer(value);
+        }
+        
+        for(const bucket_entry& bucket: m_buckets_data) {
+            bucket.serialize(serializer);
+        }
+    }
+    
+    template<class Deserializer>
+    void deserialize_impl(Deserializer& deserializer, bool hash_compatible) {
+        tsl_oh_assert(m_buckets_data.empty()); // Current hash table must be empty
+        
+        const slz_size_type version = deserialize_value<slz_size_type>(deserializer);
+        // For now we only have one version of the serialization protocol. 
+        // If it doesn't match there is a problem with the file.
+        if(version != SERIALIZATION_PROTOCOL_VERSION) {
+            TSL_OH_THROW_OR_TERMINATE(std::runtime_error, "Can't deserialize the ordered_map/set. "
+                                                          "The protocol version header is invalid.");
+        }
+        
+        const slz_size_type nb_elements = deserialize_value<slz_size_type>(deserializer);
+        const slz_size_type bucket_count_ds = deserialize_value<slz_size_type>(deserializer);
+        const float max_load_factor = deserialize_value<float>(deserializer);
+
+        if(max_load_factor < MAX_LOAD_FACTOR__MINIMUM || max_load_factor > MAX_LOAD_FACTOR__MAXIMUM) {
+            TSL_OH_THROW_OR_TERMINATE(std::runtime_error, "Invalid max_load_factor. Check that the serializer "
+                                                          "and deserializer support floats correctly as they "
+                                                          "can be converted implicitly to ints.");
+        }
+        
+        
+        this->max_load_factor(max_load_factor);
+        
+        if(bucket_count_ds == 0) {
+            tsl_oh_assert(nb_elements == 0);
+            return;
+        }
+        
+        
+        if(!hash_compatible) {
+            reserve(numeric_cast<size_type>(nb_elements, "Deserialized nb_elements is too big."));
+            for(slz_size_type el = 0; el < nb_elements; el++) {
+                insert(deserialize_value<value_type>(deserializer));
+            }
+        }
+        else {
+            m_buckets_data.reserve(numeric_cast<size_type>(bucket_count_ds, "Deserialized bucket_count is too big."));
+            m_buckets = m_buckets_data.data(),
+            m_hash_mask = m_buckets_data.capacity() - 1; 
+            
+            reserve_space_for_values(numeric_cast<size_type>(nb_elements, "Deserialized nb_elements is too big."));
+            for(slz_size_type el = 0; el < nb_elements; el++) {
+                m_values.push_back(deserialize_value<value_type>(deserializer));
+            }
+            
+            for(slz_size_type b = 0; b < bucket_count_ds; b++) {
+                m_buckets_data.push_back(bucket_entry::deserialize(deserializer));
+            }
+        }
+    }
+    
+    static std::size_t round_up_to_power_of_two(std::size_t value) {
+        if(is_power_of_two(value)) {
+            return value;
+        }
+        
+        if(value == 0) {
+            return 1;
+        }
+        
+        --value;
+        for(std::size_t i = 1; i < sizeof(std::size_t) * CHAR_BIT; i *= 2) {
+            value |= value >> i;
+        }
+        
+        return value + 1;
+    }
+    
+    static constexpr bool is_power_of_two(std::size_t value) {
+        return value != 0 && (value & (value - 1)) == 0;
+    }
+
+    
+public:
+    static const size_type DEFAULT_INIT_BUCKETS_SIZE = 0;
+    static constexpr float DEFAULT_MAX_LOAD_FACTOR = 0.75f;
+
+private:    
+    static constexpr float MAX_LOAD_FACTOR__MINIMUM = 0.1f;
+    static constexpr float MAX_LOAD_FACTOR__MAXIMUM = 0.95f;
+
+    static const size_type REHASH_ON_HIGH_NB_PROBES__NPROBES = 128;
+    static constexpr float REHASH_ON_HIGH_NB_PROBES__MIN_LOAD_FACTOR = 0.15f;
+    
+    /**
+     * Protocol version currenlty used for serialization.
+     */
+    static const slz_size_type SERIALIZATION_PROTOCOL_VERSION = 1;
+    
+    /**
+     * Return an always valid pointer to an static empty bucket_entry with last_bucket() == true.
+     */            
+    bucket_entry* static_empty_bucket_ptr() {
+        static bucket_entry empty_bucket;
+        return &empty_bucket;
+    }
+    
+private:
+    buckets_container_type m_buckets_data;
+    
+    /**
+     * Points to m_buckets_data.data() if !m_buckets_data.empty() otherwise points to static_empty_bucket_ptr.
+     * This variable is useful to avoid the cost of checking if m_buckets_data is empty when trying 
+     * to find an element.
+     * 
+     * TODO Remove m_buckets_data and only use a pointer+size instead of a pointer+vector to save some space in the ordered_hash object.
+     */
+    bucket_entry* m_buckets;
+    
+    size_type m_hash_mask;
+    
+    values_container_type m_values;
+    
+    size_type m_load_threshold;
+    float m_max_load_factor;
+    
+    bool m_grow_on_next_insert;
+};
+
+
+} // end namespace detail_ordered_hash
+
+} // end namespace tsl
+
+#endif
diff --git a/third_party/ordered-map-1.0.0/include/tsl/ordered_map.h b/third_party/ordered-map-1.0.0/include/tsl/ordered_map.h
new file mode 100644
index 0000000..1a20cca
--- /dev/null
+++ b/third_party/ordered-map-1.0.0/include/tsl/ordered_map.h
@@ -0,0 +1,863 @@
+/**
+ * MIT License
+ * 
+ * Copyright (c) 2017 Thibaut Goetghebuer-Planchon <tessil@gmx.com>
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#ifndef TSL_ORDERED_MAP_H
+#define TSL_ORDERED_MAP_H
+
+
+#include <cstddef>
+#include <cstdint>
+#include <deque>
+#include <functional>
+#include <initializer_list>
+#include <memory>
+#include <type_traits>
+#include <utility>
+#include <vector>
+#include "ordered_hash.h"
+
+
+namespace tsl {
+
+
+/**
+ * Implementation of an hash map using open addressing with robin hood with backshift delete to resolve collisions.
+ * 
+ * The particularity of this hash map is that it remembers the order in which the elements were added and
+ * provide a way to access the structure which stores these values through the 'values_container()' method. 
+ * The used container is defined by ValueTypeContainer, by default a std::deque is used (grows faster) but
+ * a std::vector may be used. In this case the map provides a 'data()' method which give a direct access 
+ * to the memory used to store the values (which can be useful to communicate with C API's).
+ * 
+ * The Key and T must be copy constructible and/or move constructible. To use `unordered_erase` they both
+ * must be swappable.
+ * 
+ * The behaviour of the hash map is undefined if the destructor of Key or T throws an exception.
+ * 
+ * By default the maximum size of a map is limited to 2^32 - 1 values, if needed this can be changed through
+ * the IndexType template parameter. Using an `uint64_t` will raise this limit to 2^64 - 1 values but each
+ * bucket will use 16 bytes instead of 8 bytes in addition to the space needed to store the values.
+ * 
+ * Iterators invalidation:
+ *  - clear, operator=, reserve, rehash: always invalidate the iterators (also invalidate end()).
+ *  - insert, emplace, emplace_hint, operator[]: when a std::vector is used as ValueTypeContainer 
+ *                                               and if size() < capacity(), only end(). 
+ *                                               Otherwise all the iterators are invalidated if an insert occurs.
+ *  - erase, unordered_erase: when a std::vector is used as ValueTypeContainer invalidate the iterator of 
+ *                            the erased element and all the ones after the erased element (including end()). 
+ *                            Otherwise all the iterators are invalidated if an erase occurs.
+ */
+template<class Key, 
+         class T, 
+         class Hash = std::hash<Key>,
+         class KeyEqual = std::equal_to<Key>,
+         class Allocator = std::allocator<std::pair<Key, T>>,
+         class ValueTypeContainer = std::deque<std::pair<Key, T>, Allocator>,
+         class IndexType = std::uint_least32_t>
+class ordered_map {
+private:
+    template<typename U>
+    using has_is_transparent = tsl::detail_ordered_hash::has_is_transparent<U>;
+    
+    class KeySelect {
+    public:
+        using key_type = Key;
+        
+        const key_type& operator()(const std::pair<Key, T>& key_value) const noexcept {
+            return key_value.first;
+        }
+        
+        key_type& operator()(std::pair<Key, T>& key_value) noexcept {
+            return key_value.first;
+        }
+    };  
+    
+    class ValueSelect {
+    public:
+        using value_type = T;
+        
+        const value_type& operator()(const std::pair<Key, T>& key_value) const noexcept {
+            return key_value.second;
+        }
+        
+        value_type& operator()(std::pair<Key, T>& key_value) noexcept {
+            return key_value.second;
+        }
+    };
+    
+    using ht = detail_ordered_hash::ordered_hash<std::pair<Key, T>, KeySelect, ValueSelect,
+                                                 Hash, KeyEqual, Allocator, ValueTypeContainer, IndexType>;
+    
+public:
+    using key_type = typename ht::key_type;
+    using mapped_type = T;
+    using value_type = typename ht::value_type;
+    using size_type = typename ht::size_type;
+    using difference_type = typename ht::difference_type;
+    using hasher = typename ht::hasher;
+    using key_equal = typename ht::key_equal;
+    using allocator_type = typename ht::allocator_type;
+    using reference = typename ht::reference;
+    using const_reference = typename ht::const_reference;
+    using pointer = typename ht::pointer;
+    using const_pointer = typename ht::const_pointer;
+    using iterator = typename ht::iterator;
+    using const_iterator = typename ht::const_iterator;
+    using reverse_iterator = typename ht::reverse_iterator;
+    using const_reverse_iterator = typename ht::const_reverse_iterator;
+    
+    using values_container_type = typename ht::values_container_type;
+    
+    
+    /*
+     * Constructors
+     */
+    ordered_map(): ordered_map(ht::DEFAULT_INIT_BUCKETS_SIZE) {
+    }
+    
+    explicit ordered_map(size_type bucket_count, 
+                         const Hash& hash = Hash(),
+                         const KeyEqual& equal = KeyEqual(),
+                         const Allocator& alloc = Allocator()): 
+                     m_ht(bucket_count, hash, equal, alloc, ht::DEFAULT_MAX_LOAD_FACTOR)
+    {
+    }
+    
+    ordered_map(size_type bucket_count,
+                const Allocator& alloc): ordered_map(bucket_count, Hash(), KeyEqual(), alloc)
+    {
+    }
+    
+    ordered_map(size_type bucket_count,
+                const Hash& hash,
+                const Allocator& alloc): ordered_map(bucket_count, hash, KeyEqual(), alloc)
+    {
+    }
+    
+    explicit ordered_map(const Allocator& alloc): ordered_map(ht::DEFAULT_INIT_BUCKETS_SIZE, alloc) {
+    }
+    
+    template<class InputIt>
+    ordered_map(InputIt first, InputIt last,
+                size_type bucket_count = ht::DEFAULT_INIT_BUCKETS_SIZE,
+                const Hash& hash = Hash(),
+                const KeyEqual& equal = KeyEqual(),
+                const Allocator& alloc = Allocator()): ordered_map(bucket_count, hash, equal, alloc)
+    {
+        insert(first, last);
+    }
+    
+    template<class InputIt>
+    ordered_map(InputIt first, InputIt last,
+                size_type bucket_count,
+                const Allocator& alloc): ordered_map(first, last, bucket_count, Hash(), KeyEqual(), alloc)
+    {
+    }
+    
+    template<class InputIt>
+    ordered_map(InputIt first, InputIt last,
+                size_type bucket_count,
+                const Hash& hash,
+                const Allocator& alloc): ordered_map(first, last, bucket_count, hash, KeyEqual(), alloc)
+    {
+    }
+
+    ordered_map(std::initializer_list<value_type> init,
+                size_type bucket_count = ht::DEFAULT_INIT_BUCKETS_SIZE,
+                const Hash& hash = Hash(),
+                const KeyEqual& equal = KeyEqual(),
+                const Allocator& alloc = Allocator()): 
+            ordered_map(init.begin(), init.end(), bucket_count, hash, equal, alloc)
+    {
+    }
+
+    ordered_map(std::initializer_list<value_type> init,
+                size_type bucket_count,
+                const Allocator& alloc): 
+            ordered_map(init.begin(), init.end(), bucket_count, Hash(), KeyEqual(), alloc)
+    {
+    }
+
+    ordered_map(std::initializer_list<value_type> init,
+                size_type bucket_count,
+                const Hash& hash,
+                const Allocator& alloc): 
+            ordered_map(init.begin(), init.end(), bucket_count, hash, KeyEqual(), alloc)
+    {
+    }
+
+    
+    ordered_map& operator=(std::initializer_list<value_type> ilist) {
+        m_ht.clear();
+        
+        m_ht.reserve(ilist.size());
+        m_ht.insert(ilist.begin(), ilist.end());
+        
+        return *this;
+    }
+    
+    allocator_type get_allocator() const { return m_ht.get_allocator(); }
+    
+
+    
+    /*
+     * Iterators
+     */
+    iterator begin() noexcept { return m_ht.begin(); }
+    const_iterator begin() const noexcept { return m_ht.begin(); }
+    const_iterator cbegin() const noexcept { return m_ht.cbegin(); }
+    
+    iterator end() noexcept { return m_ht.end(); }
+    const_iterator end() const noexcept { return m_ht.end(); }
+    const_iterator cend() const noexcept { return m_ht.cend(); }
+    
+    reverse_iterator rbegin() noexcept { return m_ht.rbegin(); }
+    const_reverse_iterator rbegin() const noexcept { return m_ht.rbegin(); }
+    const_reverse_iterator rcbegin() const noexcept { return m_ht.rcbegin(); }
+    
+    reverse_iterator rend() noexcept { return m_ht.rend(); }
+    const_reverse_iterator rend() const noexcept { return m_ht.rend(); }
+    const_reverse_iterator rcend() const noexcept { return m_ht.rcend(); }
+    
+    
+    /*
+     * Capacity
+     */
+    bool empty() const noexcept { return m_ht.empty(); }
+    size_type size() const noexcept { return m_ht.size(); }
+    size_type max_size() const noexcept { return m_ht.max_size(); }
+    
+    /*
+     * Modifiers
+     */
+    void clear() noexcept { m_ht.clear(); }
+    
+    
+    
+    std::pair<iterator, bool> insert(const value_type& value) { return m_ht.insert(value); }
+        
+    template<class P, typename std::enable_if<std::is_constructible<value_type, P&&>::value>::type* = nullptr>
+    std::pair<iterator, bool> insert(P&& value) { return m_ht.emplace(std::forward<P>(value)); }
+    
+    std::pair<iterator, bool> insert(value_type&& value) { return m_ht.insert(std::move(value)); }
+    
+    
+    iterator insert(const_iterator hint, const value_type& value) {
+        return m_ht.insert_hint(hint, value);
+    }
+        
+    template<class P, typename std::enable_if<std::is_constructible<value_type, P&&>::value>::type* = nullptr>
+    iterator insert(const_iterator hint, P&& value) {
+        return m_ht.emplace_hint(hint, std::forward<P>(value));
+    }
+    
+    iterator insert(const_iterator hint, value_type&& value) { 
+        return m_ht.insert_hint(hint, std::move(value));
+    }
+    
+    
+    template<class InputIt>
+    void insert(InputIt first, InputIt last) { m_ht.insert(first, last); }
+    void insert(std::initializer_list<value_type> ilist) { m_ht.insert(ilist.begin(), ilist.end()); }
+
+    
+    
+    
+    template<class M>
+    std::pair<iterator, bool> insert_or_assign(const key_type& k, M&& obj) { 
+        return m_ht.insert_or_assign(k, std::forward<M>(obj)); 
+    }
+
+    template<class M>
+    std::pair<iterator, bool> insert_or_assign(key_type&& k, M&& obj) { 
+        return m_ht.insert_or_assign(std::move(k), std::forward<M>(obj)); 
+    }
+    
+    
+    template<class M>
+    iterator insert_or_assign(const_iterator hint, const key_type& k, M&& obj) {
+        return m_ht.insert_or_assign(hint, k, std::forward<M>(obj));
+    }
+    
+    template<class M>
+    iterator insert_or_assign(const_iterator hint, key_type&& k, M&& obj) {
+        return m_ht.insert_or_assign(hint, std::move(k), std::forward<M>(obj));
+    }
+    
+    /**
+     * Due to the way elements are stored, emplace will need to move or copy the key-value once.
+     * The method is equivalent to insert(value_type(std::forward<Args>(args)...));
+     * 
+     * Mainly here for compatibility with the std::unordered_map interface.
+     */
+    template<class... Args>
+    std::pair<iterator, bool> emplace(Args&&... args) { return m_ht.emplace(std::forward<Args>(args)...); }
+    
+    /**
+     * Due to the way elements are stored, emplace_hint will need to move or copy the key-value once.
+     * The method is equivalent to insert(hint, value_type(std::forward<Args>(args)...));
+     * 
+     * Mainly here for compatibility with the std::unordered_map interface.
+     */
+    template <class... Args>
+    iterator emplace_hint(const_iterator hint, Args&&... args) {
+        return m_ht.emplace_hint(hint, std::forward<Args>(args)...);
+    }
+    
+    
+    
+    
+    template<class... Args>
+    std::pair<iterator, bool> try_emplace(const key_type& k, Args&&... args) { 
+        return m_ht.try_emplace(k, std::forward<Args>(args)...);
+    }
+    
+    template<class... Args>
+    std::pair<iterator, bool> try_emplace(key_type&& k, Args&&... args) {
+        return m_ht.try_emplace(std::move(k), std::forward<Args>(args)...);
+    }
+    
+    template<class... Args>
+    iterator try_emplace(const_iterator hint, const key_type& k, Args&&... args) {
+        return m_ht.try_emplace_hint(hint, k, std::forward<Args>(args)...);
+    }
+    
+    template<class... Args>
+    iterator try_emplace(const_iterator hint, key_type&& k, Args&&... args) {
+        return m_ht.try_emplace_hint(hint, std::move(k), std::forward<Args>(args)...);
+    }
+    
+    
+    
+
+    /**
+     * When erasing an element, the insert order will be preserved and no holes will be present in the container
+     * returned by 'values_container()'. 
+     * 
+     * The method is in O(n), if the order is not important 'unordered_erase(...)' method is faster with an O(1)
+     * average complexity.
+     */
+    iterator erase(iterator pos) { return m_ht.erase(pos); }
+    
+    /**
+     * @copydoc erase(iterator pos)
+     */
+    iterator erase(const_iterator pos) { return m_ht.erase(pos); }
+    
+    /**
+     * @copydoc erase(iterator pos)
+     */    
+    iterator erase(const_iterator first, const_iterator last) { return m_ht.erase(first, last); }
+    
+    /**
+     * @copydoc erase(iterator pos)
+     */    
+    size_type erase(const key_type& key) { return m_ht.erase(key); }
+    
+    /**
+     * @copydoc erase(iterator pos)
+     * 
+     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
+     * as hash_function()(key). Useful to speed-up the lookup to the value if you already have the hash.
+     */    
+    size_type erase(const key_type& key, std::size_t precalculated_hash) { 
+        return m_ht.erase(key, precalculated_hash); 
+    }
+    
+    /**
+     * @copydoc erase(iterator pos)
+     * 
+     * This overload only participates in the overload resolution if the typedef KeyEqual::is_transparent exists. 
+     * If so, K must be hashable and comparable to Key.
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
+    size_type erase(const K& key) { return m_ht.erase(key); }
+    
+    /**
+     * @copydoc erase(const key_type& key, std::size_t precalculated_hash)
+     * 
+     * This overload only participates in the overload resolution if the typedef KeyEqual::is_transparent exists. 
+     * If so, K must be hashable and comparable to Key.
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
+    size_type erase(const K& key, std::size_t precalculated_hash) { 
+        return m_ht.erase(key, precalculated_hash); 
+    }
+    
+    
+    
+    void swap(ordered_map& other) { other.m_ht.swap(m_ht); }
+    
+    /*
+     * Lookup
+     */
+    T& at(const Key& key) { return m_ht.at(key); }
+    
+    /**
+     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
+     * as hash_function()(key). Useful to speed-up the lookup if you already have the hash.
+     */
+    T& at(const Key& key, std::size_t precalculated_hash) { return m_ht.at(key, precalculated_hash); }
+    
+    
+    const T& at(const Key& key) const { return m_ht.at(key); }
+    
+    /**
+     * @copydoc at(const Key& key, std::size_t precalculated_hash)
+     */
+    const T& at(const Key& key, std::size_t precalculated_hash) const { return m_ht.at(key, precalculated_hash); }
+    
+    
+    /**
+     * This overload only participates in the overload resolution if the typedef KeyEqual::is_transparent exists. 
+     * If so, K must be hashable and comparable to Key.
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
+    T& at(const K& key) { return m_ht.at(key); }
+    
+    /**
+     * @copydoc at(const K& key)
+     * 
+     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
+     * as hash_function()(key). Useful to speed-up the lookup if you already have the hash.
+     */    
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
+    T& at(const K& key, std::size_t precalculated_hash) { return m_ht.at(key, precalculated_hash); }
+    
+    /**
+     * @copydoc at(const K& key)
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr>     
+    const T& at(const K& key) const { return m_ht.at(key); }
+    
+    /**
+     * @copydoc at(const K& key, std::size_t precalculated_hash)
+     */    
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
+    const T& at(const K& key, std::size_t precalculated_hash) const { return m_ht.at(key, precalculated_hash); }
+    
+    
+    
+    T& operator[](const Key& key) { return m_ht[key]; }    
+    T& operator[](Key&& key) { return m_ht[std::move(key)]; }
+    
+    
+    
+    size_type count(const Key& key) const { return m_ht.count(key); }
+    
+    /**
+     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
+     * as hash_function()(key). Useful to speed-up the lookup if you already have the hash.
+     */
+    size_type count(const Key& key, std::size_t precalculated_hash) const { 
+        return m_ht.count(key, precalculated_hash); 
+    }
+    
+    /**
+     * This overload only participates in the overload resolution if the typedef KeyEqual::is_transparent exists. 
+     * If so, K must be hashable and comparable to Key.
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr>     
+    size_type count(const K& key) const { return m_ht.count(key); }
+    
+    /**
+     * @copydoc count(const K& key) const
+     * 
+     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
+     * as hash_function()(key). Useful to speed-up the lookup if you already have the hash.
+     */     
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
+    size_type count(const K& key, std::size_t precalculated_hash) const { 
+        return m_ht.count(key, precalculated_hash);
+    }
+    
+    
+    
+    iterator find(const Key& key) { return m_ht.find(key); }
+    
+    /**
+     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
+     * as hash_function()(key). Useful to speed-up the lookup if you already have the hash.
+     */
+    iterator find(const Key& key, std::size_t precalculated_hash) { return m_ht.find(key, precalculated_hash); }
+    
+    const_iterator find(const Key& key) const { return m_ht.find(key); }
+    
+    /**
+     * @copydoc find(const Key& key, std::size_t precalculated_hash)
+     */
+    const_iterator find(const Key& key, std::size_t precalculated_hash) const { 
+        return m_ht.find(key, precalculated_hash);
+    }
+    
+    /**
+     * This overload only participates in the overload resolution if the typedef KeyEqual::is_transparent exists. 
+     * If so, K must be hashable and comparable to Key.
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
+    iterator find(const K& key) { return m_ht.find(key); }
+    
+    /**
+     * @copydoc find(const K& key)
+     * 
+     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
+     * as hash_function()(key). Useful to speed-up the lookup if you already have the hash.
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
+    iterator find(const K& key, std::size_t precalculated_hash) { return m_ht.find(key, precalculated_hash); }
+    
+    /**
+     * @copydoc find(const K& key)
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
+    const_iterator find(const K& key) const { return m_ht.find(key); }
+    
+    /**
+     * @copydoc find(const K& key)
+     * 
+     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
+     * as hash_function()(key). Useful to speed-up the lookup if you already have the hash.
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
+    const_iterator find(const K& key, std::size_t precalculated_hash) const { 
+        return m_ht.find(key, precalculated_hash); 
+    }
+    
+    
+    
+    bool contains(const Key& key) const { return m_ht.contains(key); }
+    
+    /**
+     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
+     * as hash_function()(key). Useful to speed-up the lookup if you already have the hash.
+     */
+    bool contains(const Key& key, std::size_t precalculated_hash) const { 
+        return m_ht.contains(key, precalculated_hash); 
+    }
+    
+    /**
+     * This overload only participates in the overload resolution if the typedef KeyEqual::is_transparent exists. 
+     * If so, K must be hashable and comparable to Key.
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
+    bool contains(const K& key) const { return m_ht.contains(key); }
+    
+    /**
+     * @copydoc contains(const K& key) const
+     * 
+     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
+     * as hash_function()(key). Useful to speed-up the lookup if you already have the hash.
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
+    bool contains(const K& key, std::size_t precalculated_hash) const { 
+        return m_ht.contains(key, precalculated_hash); 
+    }
+    
+    
+    
+    std::pair<iterator, iterator> equal_range(const Key& key) { return m_ht.equal_range(key); }
+    
+    /**
+     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
+     * as hash_function()(key). Useful to speed-up the lookup if you already have the hash.
+     */
+    std::pair<iterator, iterator> equal_range(const Key& key, std::size_t precalculated_hash) { 
+        return m_ht.equal_range(key, precalculated_hash); 
+    }
+    
+    std::pair<const_iterator, const_iterator> equal_range(const Key& key) const { return m_ht.equal_range(key); }
+    
+    /**
+     * @copydoc equal_range(const Key& key, std::size_t precalculated_hash)
+     */
+    std::pair<const_iterator, const_iterator> equal_range(const Key& key, std::size_t precalculated_hash) const { 
+        return m_ht.equal_range(key, precalculated_hash); 
+    }
+
+    /**
+     * This overload only participates in the overload resolution if the typedef KeyEqual::is_transparent exists. 
+     * If so, K must be hashable and comparable to Key.
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr>     
+    std::pair<iterator, iterator> equal_range(const K& key) { return m_ht.equal_range(key); }
+    
+    /**
+     * @copydoc equal_range(const K& key)
+     * 
+     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
+     * as hash_function()(key). Useful to speed-up the lookup if you already have the hash.
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
+    std::pair<iterator, iterator> equal_range(const K& key, std::size_t precalculated_hash) { 
+        return m_ht.equal_range(key, precalculated_hash); 
+    }
+    
+    /**
+     * @copydoc equal_range(const K& key)
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr>     
+    std::pair<const_iterator, const_iterator> equal_range(const K& key) const { return m_ht.equal_range(key); }
+    
+    /**
+     * @copydoc equal_range(const K& key, std::size_t precalculated_hash)
+     */    
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
+    std::pair<const_iterator, const_iterator> equal_range(const K& key, std::size_t precalculated_hash) const { 
+        return m_ht.equal_range(key, precalculated_hash); 
+    }
+    
+    
+    
+    /*
+     * Bucket interface 
+     */
+    size_type bucket_count() const { return m_ht.bucket_count(); }
+    size_type max_bucket_count() const { return m_ht.max_bucket_count(); }
+    
+    
+    /*
+     * Hash policy 
+     */
+    float load_factor() const { return m_ht.load_factor(); }
+    float max_load_factor() const { return m_ht.max_load_factor(); }
+    void max_load_factor(float ml) { m_ht.max_load_factor(ml); }
+    
+    void rehash(size_type count) { m_ht.rehash(count); }
+    void reserve(size_type count) { m_ht.reserve(count); }
+    
+    
+    /*
+     * Observers
+     */
+    hasher hash_function() const { return m_ht.hash_function(); }
+    key_equal key_eq() const { return m_ht.key_eq(); }
+    
+    
+    
+    /*
+     * Other
+     */
+    
+    /**
+     * Convert a const_iterator to an iterator.
+     */
+    iterator mutable_iterator(const_iterator pos) {
+        return m_ht.mutable_iterator(pos);
+    }
+    
+    /**
+     * Requires index <= size().
+     * 
+     * Return an iterator to the element at index. Return end() if index == size().
+     */
+    iterator nth(size_type index) { return m_ht.nth(index); }
+    
+    /**
+     * @copydoc nth(size_type index)
+     */
+    const_iterator nth(size_type index) const { return m_ht.nth(index); }
+    
+    
+    /**
+     * Return const_reference to the first element. Requires the container to not be empty.
+     */
+    const_reference front() const { return m_ht.front(); }
+    
+    /**
+     * Return const_reference to the last element. Requires the container to not be empty.
+     */
+    const_reference back() const { return m_ht.back(); }
+    
+    
+    /**
+     * Only available if ValueTypeContainer is a std::vector. Same as calling 'values_container().data()'.
+     */
+    template<class U = values_container_type, typename std::enable_if<tsl::detail_ordered_hash::is_vector<U>::value>::type* = nullptr>    
+    const typename values_container_type::value_type* data() const noexcept { return m_ht.data(); }
+        
+    /**
+     * Return the container in which the values are stored. The values are in the same order as the insertion order
+     * and are contiguous in the structure, no holes (size() == values_container().size()).
+     */
+    const values_container_type& values_container() const noexcept { return m_ht.values_container(); }
+
+    template<class U = values_container_type, typename std::enable_if<tsl::detail_ordered_hash::is_vector<U>::value>::type* = nullptr>    
+    size_type capacity() const noexcept { return m_ht.capacity(); }
+    
+    void shrink_to_fit() { m_ht.shrink_to_fit(); }
+    
+    
+    
+    /**
+     * Insert the value before pos shifting all the elements on the right of pos (including pos) one position 
+     * to the right.
+     * 
+     * Amortized linear time-complexity in the distance between pos and end().
+     */
+    std::pair<iterator, bool> insert_at_position(const_iterator pos, const value_type& value) { 
+        return m_ht.insert_at_position(pos, value); 
+    }
+    
+    /**
+     * @copydoc insert_at_position(const_iterator pos, const value_type& value)
+     */
+    std::pair<iterator, bool> insert_at_position(const_iterator pos, value_type&& value) { 
+        return m_ht.insert_at_position(pos, std::move(value)); 
+    }
+    
+    /**
+     * @copydoc insert_at_position(const_iterator pos, const value_type& value)
+     * 
+     * Same as insert_at_position(pos, value_type(std::forward<Args>(args)...), mainly
+     * here for coherence.
+     */
+    template<class... Args>
+    std::pair<iterator, bool> emplace_at_position(const_iterator pos, Args&&... args) {
+        return m_ht.emplace_at_position(pos, std::forward<Args>(args)...); 
+    }
+       
+    /**
+     * @copydoc insert_at_position(const_iterator pos, const value_type& value)
+     */       
+    template<class... Args>
+    std::pair<iterator, bool> try_emplace_at_position(const_iterator pos, const key_type& k, Args&&... args) { 
+        return m_ht.try_emplace_at_position(pos, k, std::forward<Args>(args)...);
+    }
+    
+    /**
+     * @copydoc insert_at_position(const_iterator pos, const value_type& value)
+     */    
+    template<class... Args>
+    std::pair<iterator, bool> try_emplace_at_position(const_iterator pos, key_type&& k, Args&&... args) {
+        return m_ht.try_emplace_at_position(pos, std::move(k), std::forward<Args>(args)...);
+    }
+    
+    
+    
+    void pop_back() { m_ht.pop_back(); }
+    
+    /**
+     * Faster erase operation with an O(1) average complexity but it doesn't preserve the insertion order.
+     * 
+     * If an erasure occurs, the last element of the map will take the place of the erased element.
+     */
+    iterator unordered_erase(iterator pos) { return m_ht.unordered_erase(pos); }
+    
+    /**
+     * @copydoc unordered_erase(iterator pos)
+     */
+    iterator unordered_erase(const_iterator pos) { return m_ht.unordered_erase(pos); }
+    
+    /**
+     * @copydoc unordered_erase(iterator pos)
+     */    
+    size_type unordered_erase(const key_type& key) { return m_ht.unordered_erase(key); }
+    
+    /**
+     * @copydoc unordered_erase(iterator pos)
+     * 
+     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
+     * as hash_function()(key). Useful to speed-up the lookup if you already have the hash.
+     */    
+    size_type unordered_erase(const key_type& key, std::size_t precalculated_hash) { 
+        return m_ht.unordered_erase(key, precalculated_hash); 
+    }
+    
+    /**
+     * @copydoc unordered_erase(iterator pos)
+     * 
+     * This overload only participates in the overload resolution if the typedef KeyEqual::is_transparent exists. 
+     * If so, K must be hashable and comparable to Key.
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
+    size_type unordered_erase(const K& key) { return m_ht.unordered_erase(key); }
+    
+    /**
+     * @copydoc unordered_erase(const K& key)
+     * 
+     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
+     * as hash_function()(key). Useful to speed-up the lookup if you already have the hash.
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
+    size_type unordered_erase(const K& key, std::size_t precalculated_hash) { 
+        return m_ht.unordered_erase(key, precalculated_hash); 
+    }
+    
+    /**
+     * Serialize the map through the `serializer` parameter.
+     * 
+     * The `serializer` parameter must be a function object that supports the following call:
+     *  - `template<typename U> void operator()(const U& value);` where the types `std::uint64_t`, `float` and `std::pair<Key, T>` must be supported for U.
+     * 
+     * The implementation leaves binary compatibility (endianness, IEEE 754 for floats, ...) of the types it serializes
+     * in the hands of the `Serializer` function object if compatibility is required.
+     */
+    template<class Serializer>
+    void serialize(Serializer& serializer) const {
+        m_ht.serialize(serializer);
+    }
+
+    /**
+     * Deserialize a previously serialized map through the `deserializer` parameter.
+     * 
+     * The `deserializer` parameter must be a function object that supports the following calls:
+     *  - `template<typename U> U operator()();` where the types `std::uint64_t`, `float` and `std::pair<Key, T>` must be supported for U.
+     * 
+     * If the deserialized hash map type is hash compatible with the serialized map, the deserialization process can be
+     * sped up by setting `hash_compatible` to true. To be hash compatible, the Hash and KeyEqual must behave the same way 
+     * than the ones used on the serialized map. The `std::size_t` must also be of the same size as the one on the platform used
+     * to serialize the map, the same apply for `IndexType`. If these criteria are not met, the behaviour is undefined with 
+     * `hash_compatible` sets to true.
+     * 
+     * The behaviour is undefined if the type `Key` and `T` of the `ordered_map` are not the same as the
+     * types used during serialization.
+     * 
+     * The implementation leaves binary compatibility (endianness, IEEE 754 for floats, size of int, ...) of the types it 
+     * deserializes in the hands of the `Deserializer` function object if compatibility is required.
+     */
+    template<class Deserializer>
+    static ordered_map deserialize(Deserializer& deserializer, bool hash_compatible = false) {
+        ordered_map map(0);
+        map.m_ht.deserialize(deserializer, hash_compatible);
+
+        return map;
+    }
+    
+    
+    
+    friend bool operator==(const ordered_map& lhs, const ordered_map& rhs) { return lhs.m_ht == rhs.m_ht; }
+    friend bool operator!=(const ordered_map& lhs, const ordered_map& rhs) { return lhs.m_ht != rhs.m_ht; }
+    friend bool operator<(const ordered_map& lhs, const ordered_map& rhs) { return lhs.m_ht < rhs.m_ht; }
+    friend bool operator<=(const ordered_map& lhs, const ordered_map& rhs) { return lhs.m_ht <= rhs.m_ht; }
+    friend bool operator>(const ordered_map& lhs, const ordered_map& rhs) { return lhs.m_ht > rhs.m_ht; }
+    friend bool operator>=(const ordered_map& lhs, const ordered_map& rhs) { return lhs.m_ht >= rhs.m_ht; }
+    
+    friend void swap(ordered_map& lhs, ordered_map& rhs) { lhs.swap(rhs); }
+
+private:
+    ht m_ht;
+};
+
+} // end namespace tsl
+
+#endif
diff --git a/third_party/ordered-map-1.0.0/include/tsl/ordered_set.h b/third_party/ordered-map-1.0.0/include/tsl/ordered_set.h
new file mode 100644
index 0000000..90a99ee
--- /dev/null
+++ b/third_party/ordered-map-1.0.0/include/tsl/ordered_set.h
@@ -0,0 +1,718 @@
+/**
+ * MIT License
+ * 
+ * Copyright (c) 2017 Thibaut Goetghebuer-Planchon <tessil@gmx.com>
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#ifndef TSL_ORDERED_SET_H
+#define TSL_ORDERED_SET_H
+
+
+#include <cstddef>
+#include <cstdint>
+#include <deque>
+#include <functional>
+#include <initializer_list>
+#include <memory>
+#include <type_traits>
+#include <utility>
+#include <vector>
+#include "ordered_hash.h"
+
+
+namespace tsl {
+
+
+/**
+ * Implementation of an hash set using open addressing with robin hood with backshift delete to resolve collisions.
+ * 
+ * The particularity of this hash set is that it remembers the order in which the elements were added and
+ * provide a way to access the structure which stores these values through the 'values_container()' method. 
+ * The used container is defined by ValueTypeContainer, by default a std::deque is used (grows faster) but
+ * a std::vector may be used. In this case the set provides a 'data()' method which give a direct access 
+ * to the memory used to store the values (which can be useful to communicate with C API's).
+ * 
+ * The Key must be copy constructible and/or move constructible. To use `unordered_erase` it also must be swappable.
+ * 
+ * The behaviour of the hash set is undefined if the destructor of Key throws an exception.
+ * 
+ * By default the maximum size of a set is limited to 2^32 - 1 values, if needed this can be changed through
+ * the IndexType template parameter. Using an `uint64_t` will raise this limit to 2^64 - 1 values but each
+ * bucket will use 16 bytes instead of 8 bytes in addition to the space needed to store the values.
+ * 
+ * Iterators invalidation:
+ *  - clear, operator=, reserve, rehash: always invalidate the iterators (also invalidate end()).
+ *  - insert, emplace, emplace_hint, operator[]: when a std::vector is used as ValueTypeContainer 
+ *                                               and if size() < capacity(), only end(). 
+ *                                               Otherwise all the iterators are invalidated if an insert occurs.
+ *  - erase, unordered_erase: when a std::vector is used as ValueTypeContainer invalidate the iterator of 
+ *                            the erased element and all the ones after the erased element (including end()). 
+ *                            Otherwise all the iterators are invalidated if an erase occurs.
+ */
+template<class Key, 
+         class Hash = std::hash<Key>,
+         class KeyEqual = std::equal_to<Key>,
+         class Allocator = std::allocator<Key>,
+         class ValueTypeContainer = std::deque<Key, Allocator>,
+         class IndexType = std::uint_least32_t>
+class ordered_set {
+private:
+    template<typename U>
+    using has_is_transparent = tsl::detail_ordered_hash::has_is_transparent<U>;
+    
+    class KeySelect {
+    public:
+        using key_type = Key;
+        
+        const key_type& operator()(const Key& key) const noexcept {
+            return key;
+        }
+        
+        key_type& operator()(Key& key) noexcept {
+            return key;
+        }
+    };
+    
+    using ht = detail_ordered_hash::ordered_hash<Key, KeySelect, void,
+                                                 Hash, KeyEqual, Allocator, ValueTypeContainer, IndexType>;
+            
+public:
+    using key_type = typename ht::key_type;
+    using value_type = typename ht::value_type;
+    using size_type = typename ht::size_type;
+    using difference_type = typename ht::difference_type;
+    using hasher = typename ht::hasher;
+    using key_equal = typename ht::key_equal;
+    using allocator_type = typename ht::allocator_type;
+    using reference = typename ht::reference;
+    using const_reference = typename ht::const_reference;
+    using pointer = typename ht::pointer;
+    using const_pointer = typename ht::const_pointer;
+    using iterator = typename ht::iterator;
+    using const_iterator = typename ht::const_iterator;
+    using reverse_iterator = typename ht::reverse_iterator;
+    using const_reverse_iterator = typename ht::const_reverse_iterator;
+    
+    using values_container_type = typename ht::values_container_type;
+
+    
+    /*
+     * Constructors
+     */
+    ordered_set(): ordered_set(ht::DEFAULT_INIT_BUCKETS_SIZE) {
+    }
+    
+    explicit ordered_set(size_type bucket_count, 
+                         const Hash& hash = Hash(),
+                         const KeyEqual& equal = KeyEqual(),
+                         const Allocator& alloc = Allocator()): 
+                        m_ht(bucket_count, hash, equal, alloc, ht::DEFAULT_MAX_LOAD_FACTOR)
+    {
+    }
+    
+    ordered_set(size_type bucket_count,
+                const Allocator& alloc): ordered_set(bucket_count, Hash(), KeyEqual(), alloc)
+    {
+    }
+    
+    ordered_set(size_type bucket_count,
+                const Hash& hash,
+                const Allocator& alloc): ordered_set(bucket_count, hash, KeyEqual(), alloc)
+    {
+    }
+    
+    explicit ordered_set(const Allocator& alloc): ordered_set(ht::DEFAULT_INIT_BUCKETS_SIZE, alloc) {
+    }
+    
+    template<class InputIt>
+    ordered_set(InputIt first, InputIt last,
+                size_type bucket_count = ht::DEFAULT_INIT_BUCKETS_SIZE,
+                const Hash& hash = Hash(),
+                const KeyEqual& equal = KeyEqual(),
+                const Allocator& alloc = Allocator()): ordered_set(bucket_count, hash, equal, alloc)
+    {
+        insert(first, last);
+    }
+    
+    template<class InputIt>
+    ordered_set(InputIt first, InputIt last,
+                size_type bucket_count,
+                const Allocator& alloc): ordered_set(first, last, bucket_count, Hash(), KeyEqual(), alloc)
+    {
+    }
+    
+    template<class InputIt>
+    ordered_set(InputIt first, InputIt last,
+                size_type bucket_count,
+                const Hash& hash,
+                const Allocator& alloc): ordered_set(first, last, bucket_count, hash, KeyEqual(), alloc)
+    {
+    }
+
+    ordered_set(std::initializer_list<value_type> init,
+                size_type bucket_count = ht::DEFAULT_INIT_BUCKETS_SIZE,
+                const Hash& hash = Hash(),
+                const KeyEqual& equal = KeyEqual(),
+                const Allocator& alloc = Allocator()): 
+            ordered_set(init.begin(), init.end(), bucket_count, hash, equal, alloc)
+    {
+    }
+
+    ordered_set(std::initializer_list<value_type> init,
+                size_type bucket_count,
+                const Allocator& alloc): 
+            ordered_set(init.begin(), init.end(), bucket_count, Hash(), KeyEqual(), alloc)
+    {
+    }
+
+    ordered_set(std::initializer_list<value_type> init,
+                size_type bucket_count,
+                const Hash& hash,
+                const Allocator& alloc): 
+            ordered_set(init.begin(), init.end(), bucket_count, hash, KeyEqual(), alloc)
+    {
+    }
+
+    
+    ordered_set& operator=(std::initializer_list<value_type> ilist) {
+        m_ht.clear();
+        
+        m_ht.reserve(ilist.size());
+        m_ht.insert(ilist.begin(), ilist.end());
+        
+        return *this;
+    }
+    
+    allocator_type get_allocator() const { return m_ht.get_allocator(); }
+    
+    
+    /*
+     * Iterators
+     */
+    iterator begin() noexcept { return m_ht.begin(); }
+    const_iterator begin() const noexcept { return m_ht.begin(); }
+    const_iterator cbegin() const noexcept { return m_ht.cbegin(); }
+    
+    iterator end() noexcept { return m_ht.end(); }
+    const_iterator end() const noexcept { return m_ht.end(); }
+    const_iterator cend() const noexcept { return m_ht.cend(); }
+    
+    reverse_iterator rbegin() noexcept { return m_ht.rbegin(); }
+    const_reverse_iterator rbegin() const noexcept { return m_ht.rbegin(); }
+    const_reverse_iterator rcbegin() const noexcept { return m_ht.rcbegin(); }
+    
+    reverse_iterator rend() noexcept { return m_ht.rend(); }
+    const_reverse_iterator rend() const noexcept { return m_ht.rend(); }
+    const_reverse_iterator rcend() const noexcept { return m_ht.rcend(); }
+    
+    
+    /*
+     * Capacity
+     */
+    bool empty() const noexcept { return m_ht.empty(); }
+    size_type size() const noexcept { return m_ht.size(); }
+    size_type max_size() const noexcept { return m_ht.max_size(); }
+    
+    /*
+     * Modifiers
+     */
+    void clear() noexcept { m_ht.clear(); }
+    
+    
+    
+    std::pair<iterator, bool> insert(const value_type& value) { return m_ht.insert(value); }
+    std::pair<iterator, bool> insert(value_type&& value) { return m_ht.insert(std::move(value)); }
+    
+    iterator insert(const_iterator hint, const value_type& value) {
+        return m_ht.insert_hint(hint, value); 
+    }
+    
+    iterator insert(const_iterator hint, value_type&& value) { 
+        return m_ht.insert_hint(hint, std::move(value)); 
+    }
+    
+    template<class InputIt>
+    void insert(InputIt first, InputIt last) { m_ht.insert(first, last); }
+    void insert(std::initializer_list<value_type> ilist) { m_ht.insert(ilist.begin(), ilist.end()); }
+
+    
+    
+    /**
+     * Due to the way elements are stored, emplace will need to move or copy the key-value once.
+     * The method is equivalent to insert(value_type(std::forward<Args>(args)...));
+     * 
+     * Mainly here for compatibility with the std::unordered_map interface.
+     */
+    template<class... Args>
+    std::pair<iterator, bool> emplace(Args&&... args) { return m_ht.emplace(std::forward<Args>(args)...); }
+    
+    /**
+     * Due to the way elements are stored, emplace_hint will need to move or copy the key-value once.
+     * The method is equivalent to insert(hint, value_type(std::forward<Args>(args)...));
+     * 
+     * Mainly here for compatibility with the std::unordered_map interface.
+     */
+    template<class... Args>
+    iterator emplace_hint(const_iterator hint, Args&&... args) {
+        return m_ht.emplace_hint(hint, std::forward<Args>(args)...); 
+    }
+
+    /**
+     * When erasing an element, the insert order will be preserved and no holes will be present in the container
+     * returned by 'values_container()'. 
+     * 
+     * The method is in O(n), if the order is not important 'unordered_erase(...)' method is faster with an O(1)
+     * average complexity.
+     */    
+    iterator erase(iterator pos) { return m_ht.erase(pos); }
+    
+    /**
+     * @copydoc erase(iterator pos)
+     */    
+    iterator erase(const_iterator pos) { return m_ht.erase(pos); }
+    
+    /**
+     * @copydoc erase(iterator pos)
+     */    
+    iterator erase(const_iterator first, const_iterator last) { return m_ht.erase(first, last); }
+    
+    /**
+     * @copydoc erase(iterator pos)
+     */    
+    size_type erase(const key_type& key) { return m_ht.erase(key); }
+    
+    /**
+     * @copydoc erase(iterator pos)
+     * 
+     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
+     * as hash_function()(key). Useful to speed-up the lookup to the value if you already have the hash.
+     */    
+    size_type erase(const key_type& key, std::size_t precalculated_hash) { 
+        return m_ht.erase(key, precalculated_hash); 
+    }
+    
+    /**
+     * @copydoc erase(iterator pos)
+     * 
+     * This overload only participates in the overload resolution if the typedef KeyEqual::is_transparent exists. 
+     * If so, K must be hashable and comparable to Key.
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
+    size_type erase(const K& key) { return m_ht.erase(key); }
+    
+    /**
+     * @copydoc erase(const key_type& key, std::size_t precalculated_hash)
+     * 
+     * This overload only participates in the overload resolution if the typedef KeyEqual::is_transparent exists. 
+     * If so, K must be hashable and comparable to Key.
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
+    size_type erase(const K& key, std::size_t precalculated_hash) { 
+        return m_ht.erase(key, precalculated_hash); 
+    }
+    
+    
+    
+    void swap(ordered_set& other) { other.m_ht.swap(m_ht); }
+    
+    /*
+     * Lookup
+     */
+    size_type count(const Key& key) const { return m_ht.count(key); }
+    
+    /**
+     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
+     * as hash_function()(key). Useful to speed-up the lookup if you already have the hash.
+     */
+    size_type count(const Key& key, std::size_t precalculated_hash) const { 
+        return m_ht.count(key, precalculated_hash); 
+    }
+    
+    /**
+     * This overload only participates in the overload resolution if the typedef KeyEqual::is_transparent exists. 
+     * If so, K must be hashable and comparable to Key.
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr>
+    size_type count(const K& key) const { return m_ht.count(key); }
+    
+    /**
+     * @copydoc count(const K& key) const
+     * 
+     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
+     * as hash_function()(key). Useful to speed-up the lookup if you already have the hash.
+     */     
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
+    size_type count(const K& key, std::size_t precalculated_hash) const { 
+        return m_ht.count(key, precalculated_hash);
+    }
+    
+    
+    
+    
+    iterator find(const Key& key) { return m_ht.find(key); }
+    
+    /**
+     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
+     * as hash_function()(key). Useful to speed-up the lookup if you already have the hash.
+     */
+    iterator find(const Key& key, std::size_t precalculated_hash) { return m_ht.find(key, precalculated_hash); }
+    
+    const_iterator find(const Key& key) const { return m_ht.find(key); }
+    
+    /**
+     * @copydoc find(const Key& key, std::size_t precalculated_hash)
+     */
+    const_iterator find(const Key& key, std::size_t precalculated_hash) const { 
+        return m_ht.find(key, precalculated_hash);
+    }
+    
+    /**
+     * This overload only participates in the overload resolution if the typedef KeyEqual::is_transparent exists. 
+     * If so, K must be hashable and comparable to Key.
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr>
+    iterator find(const K& key) { return m_ht.find(key); }
+    
+    /**
+     * @copydoc find(const K& key)
+     * 
+     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
+     * as hash_function()(key). Useful to speed-up the lookup if you already have the hash.
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
+    iterator find(const K& key, std::size_t precalculated_hash) { return m_ht.find(key, precalculated_hash); }
+    
+    /**
+     * @copydoc find(const K& key)
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr>
+    const_iterator find(const K& key) const { return m_ht.find(key); }
+    
+    /**
+     * @copydoc find(const K& key)
+     * 
+     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
+     * as hash_function()(key). Useful to speed-up the lookup if you already have the hash.
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
+    const_iterator find(const K& key, std::size_t precalculated_hash) const { 
+        return m_ht.find(key, precalculated_hash); 
+    }
+    
+    
+    
+    bool contains(const Key& key) const { return m_ht.contains(key); }
+    
+    /**
+     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
+     * as hash_function()(key). Useful to speed-up the lookup if you already have the hash.
+     */
+    bool contains(const Key& key, std::size_t precalculated_hash) const { 
+        return m_ht.contains(key, precalculated_hash); 
+    }
+    
+    /**
+     * This overload only participates in the overload resolution if the typedef KeyEqual::is_transparent exists. 
+     * If so, K must be hashable and comparable to Key.
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
+    bool contains(const K& key) const { return m_ht.contains(key); }
+    
+    /**
+     * @copydoc contains(const K& key) const
+     * 
+     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
+     * as hash_function()(key). Useful to speed-up the lookup if you already have the hash.
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
+    bool contains(const K& key, std::size_t precalculated_hash) const { 
+        return m_ht.contains(key, precalculated_hash); 
+    }
+    
+    
+    
+    std::pair<iterator, iterator> equal_range(const Key& key) { return m_ht.equal_range(key); }
+    
+    /**
+     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
+     * as hash_function()(key). Useful to speed-up the lookup if you already have the hash.
+     */
+    std::pair<iterator, iterator> equal_range(const Key& key, std::size_t precalculated_hash) { 
+        return m_ht.equal_range(key, precalculated_hash); 
+    }
+    
+    std::pair<const_iterator, const_iterator> equal_range(const Key& key) const { return m_ht.equal_range(key); }
+    
+    /**
+     * @copydoc equal_range(const Key& key, std::size_t precalculated_hash)
+     */
+    std::pair<const_iterator, const_iterator> equal_range(const Key& key, std::size_t precalculated_hash) const { 
+        return m_ht.equal_range(key, precalculated_hash); 
+    }
+    
+    /**
+     * This overload only participates in the overload resolution if the typedef KeyEqual::is_transparent exists. 
+     * If so, K must be hashable and comparable to Key.
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr>     
+    std::pair<iterator, iterator> equal_range(const K& key) { return m_ht.equal_range(key); }
+    
+    /**
+     * @copydoc equal_range(const K& key)
+     * 
+     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
+     * as hash_function()(key). Useful to speed-up the lookup if you already have the hash.
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
+    std::pair<iterator, iterator> equal_range(const K& key, std::size_t precalculated_hash) { 
+        return m_ht.equal_range(key, precalculated_hash); 
+    }
+    
+    /**
+     * @copydoc equal_range(const K& key)
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr>     
+    std::pair<const_iterator, const_iterator> equal_range(const K& key) const { return m_ht.equal_range(key); }
+    
+    /**
+     * @copydoc equal_range(const K& key, std::size_t precalculated_hash)
+     */    
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
+    std::pair<const_iterator, const_iterator> equal_range(const K& key, std::size_t precalculated_hash) const { 
+        return m_ht.equal_range(key, precalculated_hash); 
+    }
+    
+
+    /*
+     * Bucket interface 
+     */
+    size_type bucket_count() const { return m_ht.bucket_count(); }
+    size_type max_bucket_count() const { return m_ht.max_bucket_count(); }
+    
+    
+    /*
+     *  Hash policy 
+     */
+    float load_factor() const { return m_ht.load_factor(); }
+    float max_load_factor() const { return m_ht.max_load_factor(); }
+    void max_load_factor(float ml) { m_ht.max_load_factor(ml); }
+    
+    void rehash(size_type count) { m_ht.rehash(count); }
+    void reserve(size_type count) { m_ht.reserve(count); }
+    
+    
+    /*
+     * Observers
+     */
+    hasher hash_function() const { return m_ht.hash_function(); }
+    key_equal key_eq() const { return m_ht.key_eq(); }
+    
+    
+    /*
+     * Other
+     */
+    
+    /**
+     * Convert a const_iterator to an iterator.
+     */
+    iterator mutable_iterator(const_iterator pos) {
+        return m_ht.mutable_iterator(pos);
+    }
+    
+    /**
+     * Requires index <= size().
+     * 
+     * Return an iterator to the element at index. Return end() if index == size().
+     */
+    iterator nth(size_type index) { return m_ht.nth(index); }
+    
+    /**
+     * @copydoc nth(size_type index)
+     */
+    const_iterator nth(size_type index) const { return m_ht.nth(index); }
+    
+    
+    /**
+     * Return const_reference to the first element. Requires the container to not be empty.
+     */
+    const_reference front() const { return m_ht.front(); }
+    
+    /**
+     * Return const_reference to the last element. Requires the container to not be empty.
+     */
+    const_reference back() const { return m_ht.back(); }
+    
+    
+    /**
+     * Only available if ValueTypeContainer is a std::vector. Same as calling 'values_container().data()'.
+     */ 
+    template<class U = values_container_type, typename std::enable_if<tsl::detail_ordered_hash::is_vector<U>::value>::type* = nullptr>    
+    const typename values_container_type::value_type* data() const noexcept { return m_ht.data(); }
+    
+    /**
+     * Return the container in which the values are stored. The values are in the same order as the insertion order
+     * and are contiguous in the structure, no holes (size() == values_container().size()).
+     */        
+    const values_container_type& values_container() const noexcept { return m_ht.values_container(); }
+
+    template<class U = values_container_type, typename std::enable_if<tsl::detail_ordered_hash::is_vector<U>::value>::type* = nullptr>    
+    size_type capacity() const noexcept { return m_ht.capacity(); }
+    
+    void shrink_to_fit() { m_ht.shrink_to_fit(); }
+    
+    
+    
+    /**
+     * Insert the value before pos shifting all the elements on the right of pos (including pos) one position 
+     * to the right.
+     * 
+     * Amortized linear time-complexity in the distance between pos and end().
+     */
+    std::pair<iterator, bool> insert_at_position(const_iterator pos, const value_type& value) { 
+        return m_ht.insert_at_position(pos, value); 
+    }
+    
+    /**
+     * @copydoc insert_at_position(const_iterator pos, const value_type& value)
+     */
+    std::pair<iterator, bool> insert_at_position(const_iterator pos, value_type&& value) { 
+        return m_ht.insert_at_position(pos, std::move(value)); 
+    }
+    
+    /**
+     * @copydoc insert_at_position(const_iterator pos, const value_type& value)
+     * 
+     * Same as insert_at_position(pos, value_type(std::forward<Args>(args)...), mainly
+     * here for coherence.
+     */
+    template<class... Args>
+    std::pair<iterator, bool> emplace_at_position(const_iterator pos, Args&&... args) {
+        return m_ht.emplace_at_position(pos, std::forward<Args>(args)...); 
+    }
+    
+    
+    
+    void pop_back() { m_ht.pop_back(); }
+    
+    /**
+     * Faster erase operation with an O(1) average complexity but it doesn't preserve the insertion order.
+     * 
+     * If an erasure occurs, the last element of the map will take the place of the erased element.
+     */    
+    iterator unordered_erase(iterator pos) { return m_ht.unordered_erase(pos); }
+    
+    /**
+     * @copydoc unordered_erase(iterator pos)
+     */    
+    iterator unordered_erase(const_iterator pos) { return m_ht.unordered_erase(pos); }
+    
+    /**
+     * @copydoc unordered_erase(iterator pos)
+     */    
+    size_type unordered_erase(const key_type& key) { return m_ht.unordered_erase(key); }
+    
+    /**
+     * @copydoc unordered_erase(iterator pos)
+     * 
+     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
+     * as hash_function()(key). Useful to speed-up the lookup if you already have the hash.
+     */    
+    size_type unordered_erase(const key_type& key, std::size_t precalculated_hash) { 
+        return m_ht.unordered_erase(key, precalculated_hash); 
+    }
+    
+    /**
+     * @copydoc unordered_erase(iterator pos)
+     * 
+     * This overload only participates in the overload resolution if the typedef KeyEqual::is_transparent exists. 
+     * If so, K must be hashable and comparable to Key.
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
+    size_type unordered_erase(const K& key) { return m_ht.unordered_erase(key); }
+    
+    /**
+     * @copydoc unordered_erase(const K& key)
+     * 
+     * Use the hash value 'precalculated_hash' instead of hashing the key. The hash value should be the same
+     * as hash_function()(key). Useful to speed-up the lookup if you already have the hash.
+     */
+    template<class K, class KE = KeyEqual, typename std::enable_if<has_is_transparent<KE>::value>::type* = nullptr> 
+    size_type unordered_erase(const K& key, std::size_t precalculated_hash) { 
+        return m_ht.unordered_erase(key, precalculated_hash); 
+    }
+    
+    /**
+     * Serialize the set through the `serializer` parameter.
+     * 
+     * The `serializer` parameter must be a function object that supports the following call:
+     *  - `void operator()(const U& value);` where the types `std::uint64_t`, `float` and `Key` must be supported for U.
+     * 
+     * The implementation leaves binary compatibility (endianness, IEEE 754 for floats, ...) of the types it serializes
+     * in the hands of the `Serializer` function object if compatibility is required.
+     */
+    template<class Serializer>
+    void serialize(Serializer& serializer) const {
+        m_ht.serialize(serializer);
+    }
+
+    /**
+     * Deserialize a previously serialized set through the `deserializer` parameter.
+     * 
+     * The `deserializer` parameter must be a function object that supports the following calls:
+     *  - `template<typename U> U operator()();` where the types `std::uint64_t`, `float` and `Key` must be supported for U.
+     * 
+     * If the deserialized hash set type is hash compatible with the serialized set, the deserialization process can be
+     * sped up by setting `hash_compatible` to true. To be hash compatible, the Hash and KeyEqual must behave the same way 
+     * than the ones used on the serialized map. The `std::size_t` must also be of the same size as the one on the platform used
+     * to serialize the map, the same apply for `IndexType`. If these criteria are not met, the behaviour is undefined with 
+     * `hash_compatible` sets to true.
+     *
+     * The behaviour is undefined if the type `Key` of the `ordered_set` is not the same as the
+     * type used during serialization.
+     * 
+     * The implementation leaves binary compatibility (endianness, IEEE 754 for floats, size of int, ...) of the types it 
+     * deserializes in the hands of the `Deserializer` function object if compatibility is required.
+     */
+    template<class Deserializer>
+    static ordered_set deserialize(Deserializer& deserializer, bool hash_compatible = false) {
+        ordered_set set(0);
+        set.m_ht.deserialize(deserializer, hash_compatible);
+
+        return set;
+    }
+    
+    
+    
+    friend bool operator==(const ordered_set& lhs, const ordered_set& rhs) { return lhs.m_ht == rhs.m_ht; }
+    friend bool operator!=(const ordered_set& lhs, const ordered_set& rhs) { return lhs.m_ht != rhs.m_ht; }
+    friend bool operator<(const ordered_set& lhs, const ordered_set& rhs) { return lhs.m_ht < rhs.m_ht; }
+    friend bool operator<=(const ordered_set& lhs, const ordered_set& rhs) { return lhs.m_ht <= rhs.m_ht; }
+    friend bool operator>(const ordered_set& lhs, const ordered_set& rhs) { return lhs.m_ht > rhs.m_ht; }
+    friend bool operator>=(const ordered_set& lhs, const ordered_set& rhs) { return lhs.m_ht >= rhs.m_ht; }
+    
+    friend void swap(ordered_set& lhs, ordered_set& rhs) { lhs.swap(rhs); }
+    
+private:
+    ht m_ht;    
+};
+
+} // end namespace tsl
+
+#endif