fixed compilation on older implementations without std::launder

also:
- fixed `json_formatter` type deduction on older compilers
- added build configuration option for compiling examples

include/toml++/toml.h

@@ -82,6 +82,7 @@
 	#undef TOML_IMPLEMENTATION
 	#undef TOML_INLINE_FUNC_IMPL
 	#undef TOML_COMPILER_EXCEPTIONS
+	#undef TOML_LAUNDER
 #endif
 
 /// \mainpage toml++

include/toml++/toml_common.h

@@ -318,6 +318,9 @@
 TOML_PUSH_WARNINGS
 TOML_DISABLE_ALL_WARNINGS
 
+#if __has_include(<version>)
+	#include <version>
+#endif
 #include <cstdint>
 #include <cstring>		//memcpy, memset
 #include <memory>
@@ -350,6 +353,12 @@ TOML_POP_WARNINGS
 	#define TOML_STRING_PREFIX(S) S
 #endif
 
+#ifdef __cpp_lib_launder
+	#define TOML_LAUNDER(x)	std::launder(x)
+#else
+	#define TOML_LAUNDER(x)	x
+#endif
+
 ////////// FORWARD DECLARATIONS & TYPEDEFS
 // clang-format on
 

include/toml++/toml_default_formatter.h

@@ -459,6 +459,10 @@ TOML_START
 			friend std::basic_ostream<T>& operator << (std::basic_ostream<T>&, default_formatter<U>&&) TOML_MAY_THROW;
 	};
 
+	default_formatter(const table&) -> default_formatter<char>;
+	default_formatter(const array&) -> default_formatter<char>;
+	template <typename T> default_formatter(const value<T>&) -> default_formatter<char>;
+
 	template <typename CHAR>
 	inline void default_formatter<CHAR>::print_inline(const toml::table& tbl) TOML_MAY_THROW
 	{

include/toml++/toml_json_formatter.h

@@ -103,10 +103,8 @@ TOML_START
 			/// \param 	source	The source TOML object.
 			/// \param 	flags 	Format option flags.
 			TOML_NODISCARD_CTOR
-			explicit json_formatter(
+				explicit json_formatter(const toml::node& source, format_flags flags = {}) noexcept
-				const toml::node& source,
+				: base{ source, flags | format_flags::quote_dates_and_times }
-				format_flags flags = format_flags::quote_dates_and_times) noexcept
-				: base{ source, flags }
 			{}
 
 			template <typename T, typename U>
@@ -115,6 +113,10 @@ TOML_START
 			friend std::basic_ostream<T>& operator << (std::basic_ostream<T>&, json_formatter<U>&&) TOML_MAY_THROW;
 	};
 
+	json_formatter(const table&) -> json_formatter<char>;
+	json_formatter(const array&) -> json_formatter<char>;
+	template <typename T> json_formatter(const value<T>&) -> json_formatter<char>;
+
 	template <typename CHAR>
 	inline void json_formatter<CHAR>::print(const toml::table& tbl) TOML_MAY_THROW
 	{

include/toml++/toml_parser.h

@@ -52,9 +52,9 @@ TOML_START
 			void destroy() noexcept
 			{
 				if (is_err)
-					std::launder(reinterpret_cast<parse_error*>(&storage))->~parse_error();
+					TOML_LAUNDER(reinterpret_cast<parse_error*>(&storage))->~parse_error();
 				else
-					std::launder(reinterpret_cast<table*>(&storage))->~table();
+					TOML_LAUNDER(reinterpret_cast<table*>(&storage))->~table();
 			}
 
 		public:
@@ -70,38 +70,38 @@ TOML_START
 			[[nodiscard]] table& get() & noexcept
 			{
 				TOML_ASSERT(!is_err);
-				return *std::launder(reinterpret_cast<table*>(&storage));
+				return *TOML_LAUNDER(reinterpret_cast<table*>(&storage));
 			}
 			/// \brief	Returns the internal toml::table (rvalue overload).
 			[[nodiscard]] table&& get() && noexcept
 			{
 				TOML_ASSERT(!is_err);
-				return std::move(*std::launder(reinterpret_cast<table*>(&storage)));
+				return std::move(*TOML_LAUNDER(reinterpret_cast<table*>(&storage)));
 			}
 			/// \brief	Returns the internal toml::table (const lvalue overload).
 			[[nodiscard]] const table& get() const& noexcept
 			{
 				TOML_ASSERT(!is_err);
-				return *std::launder(reinterpret_cast<const table*>(&storage));
+				return *TOML_LAUNDER(reinterpret_cast<const table*>(&storage));
 			}
 
 			/// \brief	Returns the internal toml::parse_error.
 			[[nodiscard]] parse_error& error() & noexcept
 			{
 				TOML_ASSERT(is_err);
-				return *std::launder(reinterpret_cast<parse_error*>(&storage));
+				return *TOML_LAUNDER(reinterpret_cast<parse_error*>(&storage));
 			}
 			/// \brief	Returns the internal toml::parse_error (rvalue overload).
 			[[nodiscard]] parse_error&& error() && noexcept
 			{
 				TOML_ASSERT(is_err);
-				return std::move(*std::launder(reinterpret_cast<parse_error*>(&storage)));
+				return std::move(*TOML_LAUNDER(reinterpret_cast<parse_error*>(&storage)));
 			}
 			/// \brief	Returns the internal toml::parse_error (const lvalue overload).
 			[[nodiscard]] const parse_error& error() const& noexcept
 			{
 				TOML_ASSERT(is_err);
-				return *std::launder(reinterpret_cast<const parse_error*>(&storage));
+				return *TOML_LAUNDER(reinterpret_cast<const parse_error*>(&storage));
 			}
 
 			/// \brief	Returns the internal toml::table.

include/toml++/toml_version.h

@@ -5,8 +5,8 @@
 #pragma once
 
 #define TOML_LIB_MAJOR		0
-#define TOML_LIB_MINOR		4
+#define TOML_LIB_MINOR		5
-#define TOML_LIB_PATCH		4
+#define TOML_LIB_PATCH		0
 
 #define TOML_LANG_MAJOR		0
 #define TOML_LANG_MINOR		5

meson.build

@@ -1,7 +1,7 @@
 project(
 	'tomlplusplus',
 	'cpp',
-	version : '0.4.4',
+	version : '0.5.0',
 	license : 'MIT',
 	default_options : [
 		'cpp_std=c++17',
@@ -11,67 +11,6 @@ project(
 	]
 )
 
-compiler = meson.get_compiler('cpp')
-message(['compiler ID: ', compiler.get_id()])
-
-if compiler.get_id() == 'gcc'
-	add_project_arguments([
-			'-g0',
-			'-fmax-errors=5',
-			'-Wno-init-list-lifetime'
-		],
-		language : 'cpp'
-	)
-endif
-
-if compiler.get_id() == 'clang'
-	add_project_arguments([
-			'-g0',
-			'-ferror-limit=5',
-			'-fchar8_t',
-			# '-Weverything',
-			'-Wno-c++98-compat',
-			'-Wno-c++98-compat-pedantic',
-			'-Wno-float-equal',
-			'-Wno-switch-enum',
-			'-Wno-documentation-unknown-command',
-			'-Wno-padded',
-			'-Wno-weak-vtables',
-			'-Wno-double-promotion'
-			#, '-ftime-trace'
-		],
-		language : 'cpp'
-	)
-endif
-
-if compiler.get_id() == 'intel-cl'
-	add_project_arguments([
-			'/Qoption,cpp,--unicode_source_kind,UTF-8',
-			'/std=c++latest',
-			'/wd82', # storage class is not first
-			'/wd280', # selector expression is constant (why the fuck is that a warning?)
-			'/wd411', # class provides no constructor (duh, it's an aggregate)
-			'/wd1011', # missing return statement (false negative)
-			'/wd1628', # function marked [[noreturn]] returns (false positive)
-			'/wd3280' # declaration hides member (triggered in Catch2)
-		],
-		language : 'cpp'
-	)
-endif
-
-compiler_supports_char8_strings = compiler.compiles('''
-	#include <string_view>
-	#include <string>
-	using namespace std::string_view_literals;
-	std::u8string func()
-	{
-		return std::u8string{ u8"this is a test."sv };
-	}
-	''',
-	name : 'char8 string check',
-	args : [ '-std=c++2a' ]
-)
-
 tomlplusplus_dep = declare_dependency(
 	include_directories : include_directories('include'),
 	version : meson.project_version(),
@@ -84,11 +23,77 @@ else
 	build_tests = get_option('BUILD_TESTS').enabled()
 endif
 
-if build_tests
+build_examples = false
-	inc = include_directories('include', 'extern')
+if get_option('BUILD_EXAMPLES').auto()
-	subdir('tests')
+	build_examples = (not meson.is_subproject())
 else
-	message('Not building tests')
+	build_examples = get_option('BUILD_EXAMPLES').enabled()
+endif
+
+if build_tests or build_examples
+
+	compiler = meson.get_compiler('cpp')
+	message(['compiler ID: ', compiler.get_id()])
+	message(['compiler version: ', compiler.version()])
+
+	if compiler.get_id() == 'gcc'
+		add_project_arguments([
+				'-g0',
+				'-fmax-errors=5',
+				'-Wno-init-list-lifetime'
+			],
+			language : 'cpp'
+		)
+	endif
+
+	if compiler.get_id() == 'clang'
+		add_project_arguments([
+				'-g0',
+				'-ferror-limit=5',
+				'-fchar8_t',
+				# '-Weverything',
+				'-Wno-c++98-compat',
+				'-Wno-c++98-compat-pedantic',
+				'-Wno-float-equal',
+				'-Wno-switch-enum',
+				'-Wno-documentation-unknown-command',
+				'-Wno-padded',
+				'-Wno-weak-vtables',
+				'-Wno-double-promotion'
+				#, '-ftime-trace'
+			],
+			language : 'cpp'
+		)
+	endif
+
+	if compiler.get_id() == 'intel-cl'
+		add_project_arguments([
+				'/Qoption,cpp,--unicode_source_kind,UTF-8',
+				'/std=c++latest',
+				'/wd82', # storage class is not first
+				'/wd280', # selector expression is constant (why the fuck is that a warning?)
+				'/wd411', # class provides no constructor (duh, it's an aggregate)
+				'/wd1011', # missing return statement (false negative)
+				'/wd1628', # function marked [[noreturn]] returns (false positive)
+				'/wd3280' # declaration hides member (triggered in Catch2)
+			],
+			language : 'cpp'
+		)
+	endif
+
+	inc = include_directories('include', 'extern')
+
+	if build_tests
+		subdir('tests')
+	else
+		message('Not building tests')
+	endif
+
+	if build_examples
+		subdir('examples')
+	else
+		message('Not building examples')
+	endif
+
 endif
 
-# subdir('examples')

meson_options.txt

@@ -1 +1,2 @@
 option('BUILD_TESTS', type : 'feature', value : 'auto', description : 'Whether to build tests (defaults to auto: only if not a subproject)')
+option('BUILD_EXAMPLES', type : 'feature', value : 'auto', description : 'Whether to build examples (defaults to auto: only if not a subproject)')

tests/meson.build

@@ -21,7 +21,18 @@ toml_char8_strings = '-DTOML_CHAR_8_STRINGS=1'
 manually_set_cpp_std = 'cpp_std=none'
 cpp20 = '-std=c++2a'
 use_tloptional = '-DTARTANLLAMA_OPTIONAL'
-
+compiler_supports_char8_strings = compiler.compiles('''
+	#include <string_view>
+	#include <string>
+	using namespace std::string_view_literals;
+	std::u8string func()
+	{
+		return std::u8string{ u8"this is a test."sv };
+	}
+	''',
+	name : 'char8 string check',
+	args : [ '-std=c++2a' ]
+)
 
 ############################################################################
 ### char

toml.hpp

@@ -1,6 +1,6 @@
 //----------------------------------------------------------------------------------------------------------------------
 //
-// toml++ v0.4.4
+// toml++ v0.5.0
 // https://github.com/marzer/tomlplusplus
 // SPDX-License-Identifier: MIT
 //
@@ -298,8 +298,8 @@
 #endif
 
 #define TOML_LIB_MAJOR		0
-#define TOML_LIB_MINOR		4
+#define TOML_LIB_MINOR		5
-#define TOML_LIB_PATCH		4
+#define TOML_LIB_PATCH		0
 
 #define TOML_LANG_MAJOR		0
 #define TOML_LANG_MINOR		5
@@ -363,6 +363,9 @@
 TOML_PUSH_WARNINGS
 TOML_DISABLE_ALL_WARNINGS
 
+#if __has_include(<version>)
+	#include <version>
+#endif
 #include <cstdint>
 #include <cstring>		//memcpy, memset
 #include <memory>
@@ -395,6 +398,12 @@ TOML_POP_WARNINGS
 	#define TOML_STRING_PREFIX(S) S
 #endif
 
+#ifdef __cpp_lib_launder
+	#define TOML_LAUNDER(x)	std::launder(x)
+#else
+	#define TOML_LAUNDER(x)	x
+#endif
+
 namespace toml { }
 
 TOML_START
@@ -4721,9 +4730,9 @@ TOML_START
 			void destroy() noexcept
 			{
 				if (is_err)
-					std::launder(reinterpret_cast<parse_error*>(&storage))->~parse_error();
+					TOML_LAUNDER(reinterpret_cast<parse_error*>(&storage))->~parse_error();
 				else
-					std::launder(reinterpret_cast<table*>(&storage))->~table();
+					TOML_LAUNDER(reinterpret_cast<table*>(&storage))->~table();
 			}
 
 		public:
@@ -4734,33 +4743,33 @@ TOML_START
 			[[nodiscard]] table& get() & noexcept
 			{
 				TOML_ASSERT(!is_err);
-				return *std::launder(reinterpret_cast<table*>(&storage));
+				return *TOML_LAUNDER(reinterpret_cast<table*>(&storage));
 			}
 			[[nodiscard]] table&& get() && noexcept
 			{
 				TOML_ASSERT(!is_err);
-				return std::move(*std::launder(reinterpret_cast<table*>(&storage)));
+				return std::move(*TOML_LAUNDER(reinterpret_cast<table*>(&storage)));
 			}
 			[[nodiscard]] const table& get() const& noexcept
 			{
 				TOML_ASSERT(!is_err);
-				return *std::launder(reinterpret_cast<const table*>(&storage));
+				return *TOML_LAUNDER(reinterpret_cast<const table*>(&storage));
 			}
 
 			[[nodiscard]] parse_error& error() & noexcept
 			{
 				TOML_ASSERT(is_err);
-				return *std::launder(reinterpret_cast<parse_error*>(&storage));
+				return *TOML_LAUNDER(reinterpret_cast<parse_error*>(&storage));
 			}
 			[[nodiscard]] parse_error&& error() && noexcept
 			{
 				TOML_ASSERT(is_err);
-				return std::move(*std::launder(reinterpret_cast<parse_error*>(&storage)));
+				return std::move(*TOML_LAUNDER(reinterpret_cast<parse_error*>(&storage)));
 			}
 			[[nodiscard]] const parse_error& error() const& noexcept
 			{
 				TOML_ASSERT(is_err);
-				return *std::launder(reinterpret_cast<const parse_error*>(&storage));
+				return *TOML_LAUNDER(reinterpret_cast<const parse_error*>(&storage));
 			}
 
 			[[nodiscard]] operator table& () noexcept { return get(); }
@@ -5495,6 +5504,10 @@ TOML_START
 			friend std::basic_ostream<T>& operator << (std::basic_ostream<T>&, default_formatter<U>&&) TOML_MAY_THROW;
 	};
 
+	default_formatter(const table&) -> default_formatter<char>;
+	default_formatter(const array&) -> default_formatter<char>;
+	template <typename T> default_formatter(const value<T>&) -> default_formatter<char>;
+
 	template <typename CHAR>
 	inline void default_formatter<CHAR>::print_inline(const toml::table& tbl) TOML_MAY_THROW
 	{
@@ -5626,10 +5639,8 @@ TOML_START
 		public:
 
 			TOML_NODISCARD_CTOR
-			explicit json_formatter(
+				explicit json_formatter(const toml::node& source, format_flags flags = {}) noexcept
-				const toml::node& source,
+				: base{ source, flags | format_flags::quote_dates_and_times }
-				format_flags flags = format_flags::quote_dates_and_times) noexcept
-				: base{ source, flags }
 			{}
 
 			template <typename T, typename U>
@@ -5638,6 +5649,10 @@ TOML_START
 			friend std::basic_ostream<T>& operator << (std::basic_ostream<T>&, json_formatter<U>&&) TOML_MAY_THROW;
 	};
 
+	json_formatter(const table&) -> json_formatter<char>;
+	json_formatter(const array&) -> json_formatter<char>;
+	template <typename T> json_formatter(const value<T>&) -> json_formatter<char>;
+
 	template <typename CHAR>
 	inline void json_formatter<CHAR>::print(const toml::table& tbl) TOML_MAY_THROW
 	{
@@ -9188,6 +9203,7 @@ TOML_END
 	#undef TOML_IMPLEMENTATION
 	#undef TOML_INLINE_FUNC_IMPL
 	#undef TOML_COMPILER_EXCEPTIONS
+	#undef TOML_LAUNDER
 #endif
 
 #ifdef __GNUC__