Fix warnings on AppleClang 12

.gitignore

@@ -8,3 +8,4 @@ temp.*
 build*/
 .idea/
 cmake-build*/
+CMakeLists.txt.user

include/literals.h

@@ -1,15 +1,15 @@
 #pragma once
 
-static const char *hello_world = R"lit(
+static const char *hello_world = &R"lit(
 #include <iostream>
 
 int %s() {
     std::cout << "Hello World!\n";
     return 0;
 }
-)lit" + 1; // skip initial newline
+)lit"[1]; // skip initial newline
 
-static const char *cmake_toml = R"lit(
+static const char *cmake_toml = &R"lit(
 [cmake]
 version = "3.15"
 # subdirs = []
@@ -43,4 +43,4 @@ include-directories = ["include"]
 [[install]]
 %s = ["%s"]
 destination = "${CMAKE_INSTALL_PREFIX}/%s"
-)lit" + 1; // skip initial newline
+)lit"[1]; // skip initial newline

src/cmkrlib/gen.cpp

@@ -272,7 +272,7 @@ struct Command {
     CommandEndl operator()(Ts &&...values) {
         generated = true;
         ss << indent(depth) << command << '(';
-        std::initializer_list<bool>{print_arg(values)...};
+        (void)std::initializer_list<bool>{print_arg(values)...};
         if (had_newline)
             ss << '\n';
         ss << ")\n";