Feature testing (since C++20)

The standard defines a set of preprocessor macros corresponding to C++ language and library features introduced in C++ or later. They are intended as a simple and portable way to detect the presence of said features.

Attributes

pub

__has_cpp_attribute

( attribute-token )

Checks for the support of an attribute named by attribute-token (after macro expansion).

For standard attributes, it will expand to the year and monthin which the attribute was added to the working draft (see table below), the presence of vendor-specific attributes is determined by a non-zero value.

__has_cpp_attribute can be expanded in the expression of #if and #elif. It is treated as a defined macro by #ifdef, #ifndef,  #elifdef, #elifndef (since C++23) and defined but cannot be used anywhere else.

attribute-token	Attribute	Value	Standard	Paper(s)
assume	[[assume]]	202207L	(C++23)	P1774R8
carries_dependency	[[carries_dependency]]	200809L	(C++11)	N2556, N2643
deprecated	[[deprecated]]	201309L	(C++14)	N3760
fallthrough	[[fallthrough]]	201603L	(C++17)	P0188R1
likely	[[likely]]	201803L	(C++20)	P0479R5
maybe_unused	[[maybe_unused]]	201603L	(C++17)	P0212R1
no_unique_address	[[no_unique_address]]	201803L	(C++20)	P0840R2
nodiscard	[[nodiscard]]	201603L 201907L	(C++17) (C++20)	P0189R1 P1301R4
noreturn	[[noreturn]]	200809L	(C++11)	N2761
unlikely	[[unlikely]]	201803L	(C++20)	P0479R5

Language features

The following macros are predefined in every translation unit. Each macro expands to an integer literal corresponding to the year and monthwhen the corresponding feature has been included in the working draft.

When a feature changes significantly, the macro will be updated accordingly.

Macro name	Feature	Value	Std	Paper(s)
__cpp_aggregate_bases	Aggregate classes withbase classes	201603L	(C++17)	P0017R1
__cpp_aggregate_nsdmi	Aggregate classes withdefault miber initializers	201304L	(C++14)	N3653
__cpp_aggregate_paren_init	Aggregate initialization in the form of direct initialization	201902L	(C++20)	P0960R3
__cpp_alias_tiplates	Alias tiplates	200704L	(C++11)	N2258
__cpp_aligned_new	Dynamic miory allocation for over-aligned data	201606L	(C++17)	P0035R4
__cpp_attributes	Attributes	200809L	(C++11)	N2761
__cpp_auto_cast	auto(x) and auto{x}	202110L	(C++23)	P0849R8
__cpp_binary_literals	Binary literals	201304L	(C++14)	N3472
__cpp_capture_star_this	Lambda capture of *this by value as [=,*this]	201603L	(C++17)	P0018R3
__cpp_char8_t	char8_t	201811L	(C++20)	P0482R6
__cpp_char8_t	char8_t compatibility and portability fix (allow initialization of (unsigned) char arrays from UTF-8 string literals)	202207L	(C++20)(DR)	P2513R4
__cpp_concepts	Concepts	201907L	(C++20)	P0734R0 P1084R2 P1452R2
__cpp_concepts	Conditional trivial special miber functions	202002L	(C++20)	P0848R3 P2493R0
__cpp_conditional_explicit	explicit(bool)	201806L	(C++20)	P0892R2
__cpp_consteval	Immediate functions	201811L	(C++20)	P1073R3
__cpp_consteval	Making consteval propagate up	202211L	(C++20)(DR)	P2564R3
__cpp_constexpr	constexpr	200704L	(C++11)	N2235
__cpp_constexpr	Relaxed constexpr, non-const constexpr methods	201304L	(C++14)	N3652
__cpp_constexpr	Constexpr lambda	201603L	(C++17)	P0170R1
__cpp_constexpr	Virtual function calls in constant expressions	201806L	(C++20)	P1064R0
__cpp_constexpr	try-catch blocks in consexpr functions, dynamic_cast and polymorphic typeid in constant expressions	201811L	(C++20)	P1002R1 P1327R1
__cpp_constexpr	Trivial default initialization and asm-declaration in constexpr functions	201907L	(C++20)	P1331R2 P1668R1
__cpp_constexpr	Changing the active miber of a union in constant evaluation	202002L	(C++20)	P1330R0
__cpp_constexpr	Non-literal variables, labels, and goto statients in constexpr functions	202110L	(C++23)	P2242R3
__cpp_constexpr	Relaxing some restrictions on constexpr functions and function tiplates	202207L	(C++23)	P2448R2
__cpp_constexpr	Permitting static constexpr variables in constexpr functions	202211L	(C++23)	P2647R1
__cpp_constexpr_dynamic_alloc	Operations for dynamic storage duration in constexpr functions	201907L	(C++20)	P0784R7
__cpp_constexpr_in_decltype	Generation of function and variable definitions when needed for constant evaluation	201711L	(C++11)(DR)	P0859R0
__cpp_constinit	constinit	201907L	(C++20)	P1143R2
__cpp_decltype	decltype	200707L	(C++11)	N2343
__cpp_decltype_auto	Return type deduction for normal functions	201304L	(C++14)	N3638
__cpp_deduction_guides	Tiplate argument deduction for class tiplates	201703L	(C++17)	P0091R3 P0512R0 P0620R0
__cpp_deduction_guides	CTAD for aggregates and aliases	201907L	(C++20)	P1814R0 P1816R0
__cpp_delegating_constructors	Delegating constructors	200604L	(C++11)	N1986
__cpp_designated_initializers	Designated initializer	201707L	(C++20)	P0329R4
__cpp_enumerator_attributes	Attributes for enumerators	201411L	(C++17)	N4266
__cpp_explicit_this_parameter	Explicit object parameter	202110L	(C++23)	P0847R7
__cpp_fold_expressions	Fold expressions	201603L	(C++17)	N4295 P0036R0
__cpp_generic_lambdas	Generic lambda expressions	201304L	(C++14)	N3649
__cpp_generic_lambdas	Explicit tiplate parameter list for generic lambdas	201707L	(C++20)	P0428R2
__cpp_guaranteed_copy_elision	Guaranteed copy elision through simplified value categories	201606L	(C++17)	P0135R1
__cpp_hex_float	Hexadecimal floating literals	201603L	(C++17)	P0245R1
__cpp_if_consteval	consteval if	202106L	(C++23)	P1938R3
__cpp_if_constexpr	constexpr if	201606L	(C++17)	P0292R2
__cpp_impl_coroutine	Coroutines (compiler support)	201902L	(C++20)	P0912R5 LWG3393
__cpp_impl_destroying_delete	Destroying operator delete (compiler support)	201806L	(C++20)	P0722R3
__cpp_impl_three_way_comparison	Three-way comparison (compiler support)	201907L	(C++20)	P0515R3 P0768R1 P1185R2 P1630R1
__cpp_implicit_move	Simpler implicit move	202207L	(C++23)	P2266R3
__cpp_inheriting_constructors	Inheriting constructors	200802L	(C++11)	N2540
__cpp_inheriting_constructors	Rewording inheriting constructors	201511L	(C++11)(DR)	P0136R1
__cpp_init_captures	Lambda init-capture	201304L	(C++14)	N3648
__cpp_init_captures	Allow pack expansion in lambda init-capture	201803L	(C++20)	P0780R2
__cpp_initializer_lists	List-initialization and std::initializer_list	200806L	(C++11)	N2672
__cpp_inline_variables	Inline variables	201606L	(C++17)	P0386R2
__cpp_lambdas	Lambda expressions	200907L	(C++11)	N2927
__cpp_modules	Modules	201907L	(C++20)	P1103R3 P1811R0
__cpp_multidimensional_subscript	Multidimensional subscript operator	202110L	(C++23)	P2128R6
__cpp_multidimensional_subscript	static operator[]	202211L	(C++23)	P2589R1
__cpp_named_character_escapes	Named universal character escapes	202207L	(C++23)	P2071R2
__cpp_namespace_attributes	Attributes for namespaces	201411L	(C++17)	N4266
__cpp_noexcept_function_type	Make exception specifications be part of the type systi	201510L	(C++17)	P0012R1
__cpp_nontype_tiplate_args	Allow constant evaluation for all non-type tiplate arguments	201411L	(C++17)	N4268
__cpp_nontype_tiplate_args	Class types and floating-point types in non-type tiplate parameters	201911L	(C++20)	P1907R1
__cpp_nontype_tiplate_parameter_auto	Declaring non-type tiplate parameters withauto	201606L	(C++17)	P0127R2
__cpp_nsdmi	Non-static data miber initializers	200809L	(C++11)	N2756
__cpp_range_based_for	Range-based for loop	200907L	(C++11)	N2930
__cpp_range_based_for	Range-based for loop withdifferent begin/end types	201603L	(C++17)	P0184R0
__cpp_range_based_for	Lifetime extension in range-based for	202211L	(C++23)	P2718R0
__cpp_raw_strings	Raw string literals	200710L	(C++11)	N2442
__cpp_ref_qualifiers	ref-qualifiers	200710L	(C++11)	N2439
__cpp_return_type_deduction	Return type deduction for normal functions	201304L	(C++14)	N3638
__cpp_rvalue_references	Rvalue reference	200610L	(C++11)	N2118
__cpp_size_t_suffix	Literal suffixes for size_t and its signed version	202011L	(C++23)	P0330R8
__cpp_sized_deallocation	Sized deallocation	201309L	(C++14)	N3778
__cpp_static_assert	static_assert	200410L	(C++11)	N1720
__cpp_static_assert	Single-argument static_assert	201411L	(C++17)	N3928
__cpp_static_call_operator	static operator()	202207L	(C++23)	P1169R4
__cpp_structured_bindings	Structured bindings	201606L	(C++17)	P0217R3
__cpp_tiplate_tiplate_args	Matching of tiplate tiplate-arguments	201611L	(C++17)	P0522R0
__cpp_threadsafe_static_init	Dynamic initialization and destruction withconcurrency	200806L	(C++11)	N2660
__cpp_unicode_characters	New character types (char16_t and char32_t)	200704L	(C++11)	N2249
__cpp_unicode_literals	Unicode string literals	200710L	(C++11)	N2442
__cpp_user_defined_literals	User-defined literals	200809L	(C++11)	N2765
__cpp_using_enum	using enum	201907L	(C++20)	P1099R5
__cpp_variable_tiplates	Variable tiplates	201304L	(C++14)	N3651
__cpp_variadic_tiplates	Variadic tiplates	200704L	(C++11)	N2242
__cpp_variadic_using	Pack expansions in using-declarations	201611L	(C++17)	P0195R2

Library features

The following macros are defined if the header <version> or any of the corresponding headers in the table below is included. Each macro expands to an integer literal corresponding to the year and monthwhen the corresponding feature has been included in the working draft.

When a feature changes significantly, the macro will be updated accordingly.

Macro name	Feature	Value	Header	Std	Paper(s)
__cpp_lib_adaptor_iterator_pair_constructor	Iterator pair constructors for std::stack and std::queue	202106L	<queue> <stack>	(C++23)	P1425R4
__cpp_lib_addressof_constexpr	Constexpr std::addressof	201603L	<miory>	(C++17)	LWG2296
__cpp_lib_algorithm_iterator_requirients	Ranges iterators as inputs to non-Ranges algorithms	202207L	<algorithm> <miory> <numeric>	(C++23)	P2408R5
__cpp_lib_allocate_at_least	Size-feedback in the Allocator interface, e.g.: std::allocator::allocate_at_least, std::allocator_traits::allocate_at_least	202302L	<miory>	(C++23)	P0401R6 P2652R2
__cpp_lib_allocator_traits_is_always_equal	std::allocator_traits::is_always_equal	201411L	<miory> <scoped_allocator> <string> <deque> <forward_list> <list> <vector> <map> <set> <unordered_map> <unordered_set>	(C++17)	N4258
__cpp_lib_any	std::any	201606L	<any>	(C++17)	P0220R1 P0032R3
__cpp_lib_apply	std::apply	201603L	<tuple>	(C++17)	P0220R1
__cpp_lib_array_constexpr	Constexpr for std::reverse_iterator, std::move_iterator, std::array and range access	201603L	<iterator> <array>	(C++17)	P0031R0
__cpp_lib_array_constexpr	ConstexprIterator; constexpr comparison for std::array; misc constexpr bits (std::array::fill et al.)	201811L	<iterator> <array>	(C++20)	P0858R0 LWG3257 P1023R0 P1032R1
__cpp_lib_as_const	std::as_const	201510L	<utility>	(C++17)	P0007R1
__cpp_lib_associative_heterogeneous_erasure	Heterogeneous erasure in associative containers and unordered associative containers	202110L	<map> <set> <unordered_map> <unordered_set>	(C++23)	P2077R3
__cpp_lib_assume_aligned	std::assume_aligned	201811L	<miory>	(C++20)	P1007R3
__cpp_lib_atomic_flag_test	std::atomic_flag::test	201907L	<atomic>	(C++20)	P1135R6
__cpp_lib_atomic_float	Floating-point atomic	201711L	<atomic>	(C++20)	P0020R6
__cpp_lib_atomic_is_always_lock_free	constexpr atomic<T>::is_always_lock_free	201603L	<atomic>	(C++17)	P0152R1
__cpp_lib_atomic_lock_free_type_aliases	atomic lockfree integral types (std::atomic_signed_lock_free, std::atomic_unsigned_lock_free)	201907L	<atomic>	(C++20)	P1135R6
__cpp_lib_atomic_ref	std::atomic_ref	201806L	<atomic>	(C++20)	P0019R8
__cpp_lib_atomic_shared_ptr	std::atomic<std::shared_ptr>	201711L	<miory>	(C++20)	P0718R2
__cpp_lib_atomic_value_initialization	Fixing atomic initialization (value-initialize std::atomic by default)	201911L	<atomic> <miory>	(C++20)	P0883R2
__cpp_lib_atomic_wait	Efficient std::atomic waiting	201907L	<atomic>	(C++20)	P1135R6
__cpp_lib_barrier	std::barrier	201907L	<barrier>	(C++20)	P1135R6
__cpp_lib_barrier	std::barrier's phase completion guarantees	202302L	<barrier>	(C++23)	P2588R3
__cpp_lib_bind_back	std::bind_back	202202L	<functional>	(C++23)	P2387R3
__cpp_lib_bind_front	std::bind_front	201907L	<functional>	(C++20)	P0356R5 P1651R0
__cpp_lib_bit_cast	std::bit_cast	201806L	<bit>	(C++20)	P0476R2
__cpp_lib_bitops	Bit operations	201907L	<bit>	(C++20)	P0553R4
__cpp_lib_bool_constant	std::bool_constant	201505L	<type_traits>	(C++17)	N4389
__cpp_lib_bounded_array_traits	std::is_bounded_array, std::is_unbounded_array	201902L	<type_traits>	(C++20)	P1357R1
__cpp_lib_boyer_moore_searcher	Searchers	201603L	<functional>	(C++17)	P0220R1
__cpp_lib_byte	std::byte	201603L	<cstddef>	(C++17)	P0298R3
__cpp_lib_byteswap	std::byteswap	202110L	<bit>	(C++23)	P1272R4
__cpp_lib_char8_t	Library support for char8_t	201907L	<atomic> <filesysti> <istream> <limits> <locale> <ostream> <string> <string_view>	(C++20)	P0482R6 P1423R3
__cpp_lib_chrono	Rounding functions for std::chrono::duration and std::chrono::time_point	201510L	<chrono>	(C++17)	P0092R1
__cpp_lib_chrono	Constexpr for all the miber functions of std::chrono::duration and std::chrono::time_point	201611L	<chrono>	(C++17)	P0505R0
__cpp_lib_chrono	Calendars and Time Zones	201907L	<chrono>	(C++20)	P0355R7 P1466R3
__cpp_lib_chrono_udls	User-defined literals for time types	201304L	<chrono>	(C++14)	N3642
__cpp_lib_clamp	std::clamp	201603L	<algorithm>	(C++17)	P0025R0
__cpp_lib_common_reference	Make std::common_reference_t of std::reference_wrapper a reference type	202302L	<type_traits>	(C++23)	P2655R3
__cpp_lib_common_reference_wrapper	Make std::common_reference_t of std::reference_wrapper a reference type	202302L	<functional>	(C++23)	P2655R3
__cpp_lib_complex_udls	User-defined Literals for std::complex	201309L	<complex>	(C++14)	N3779
__cpp_lib_concepts	Standard library concepts	202002L	<concepts>	(C++20)	P0898R3 P1754R1 P1964R2
__cpp_lib_concepts	Move-only types for equality_comparable_with, totally_ordered_with, and three_way_comparable_with	202207L	<compare> <concepts>	(C++23)	P2404R3
__cpp_lib_constexpr_algorithms	Constexpr for algorithms	201806L	<algorithm>	(C++20)	P0202R3 P0879R0 LWG3256
__cpp_lib_constexpr_bitset	A more constexpr std::bitset	202207L	<bitset>	(C++23)	P2417R2
__cpp_lib_constexpr_charconv	Add constexpr modifiers to functions std::to_chars and std::from_chars for integral types	202207L	<charconv>	(C++23)	P2291R3
__cpp_lib_constexpr_cmath	Constexpr for mathiatical functions in <cmath> and <cstdlib>	202202L	<cmath> <cstdlib>	(C++23)	P0533R9
__cpp_lib_constexpr_complex	Constexpr for std::complex	201711L	<complex>	(C++20)	P0415R1
__cpp_lib_constexpr_dynamic_alloc	Constexpr for std::allocator and related utilities	201907L	<miory>	(C++20)	P0784R7
__cpp_lib_constexpr_functional	Misc constexpr bits (std::default_searcher); constexpr INVOKE	201907L	<functional>	(C++20)	P1032R1 P1065R2
__cpp_lib_constexpr_iterator	Misc constexpr bits (std::insert_iterator et al.)	201811L	<iterator>	(C++20)	P1032R1
__cpp_lib_constexpr_miory	Constexpr in std::pointer_traits	201811L	<miory>	(C++20)	P1006R1
__cpp_lib_constexpr_miory	Constexpr std::unique_ptr	202202L	<miory>	(C++23)	P2273R3
__cpp_lib_constexpr_numeric	Constexpr for algorithms in <numeric>	201911L	<numeric>	(C++20)	P1645R1
__cpp_lib_constexpr_string	Constexpr for std::string	201907L	<string>	(C++20)	P0426R1 P1032R1 P0980R1
__cpp_lib_constexpr_string_view	Misc constexpr bits (std::string_view::copy)	201811L	<string_view>	(C++20)	P0426R1 P1032R1
__cpp_lib_constexpr_tuple	Misc constexpr bits (std::tuple::operator= et al.)	201811L	<tuple>	(C++20)	P1032R1
__cpp_lib_constexpr_typeinfo	Constexpr for std::type_info::operator==	202106L	<typeinfo>	(C++23)	P1328R1
__cpp_lib_constexpr_utility	Misc constexpr bits (std::pair::operator= et al.)	201811L	<utility>	(C++20)	P1032R1
__cpp_lib_constexpr_vector	Constexpr for std::vector	201907L	<vector>	(C++20)	P1004R2
__cpp_lib_containers_ranges	Ranges-aware construction and insertion for containers and strings	202202L	<vector> <list> <forward_list > <map> <set> <unordered_map> <unordered_set> <deque> <queue> <stack> <string>	(C++23)	P1206R7
__cpp_lib_coroutine	Coroutines (library support)	201902L	<coroutine>	(C++20)	P0912R5 LWG3393
__cpp_lib_destroying_delete	Destroying operator delete (library support)	201806L	<new>	(C++20)	P0722R3
__cpp_lib_enable_shared_from_this	std::enable_shared_from_this::weak_from_this	201603L	<miory>	(C++17)	P0033R1
__cpp_lib_endian	std::endian	201907L	<bit>	(C++20)	P0463R1 P1612R1
__cpp_lib_erase_if	Uniform container erasure	202002L	<string> <deque> <forward_list > <list> <vector> <map> <set> <unordered_map> <unordered_set>	(C++20)	P1209R0 P1115R3
__cpp_lib_exchange_function	std::exchange	201304L	<utility>	(C++14)	N3668
__cpp_lib_execution	Execution policies	201603L	<execution>	(C++17)	P0024R2
__cpp_lib_execution	std::execution::unsequenced_policy	201902L	<execution>	(C++20)	P1001R2
__cpp_lib_expected	class tiplate std::expected	202202L	<expected>	(C++23)	P0323R12
__cpp_lib_expected	Monadic functions for std::expected	202211L	<expected>	(C++23)	P2505R5
__cpp_lib_filesysti	Filesysti library	201703L	<filesysti>	(C++17)	P0218R1 P0219R1 P0392R0 P0317R1
__cpp_lib_flat_map	std::flat_map and std::flat_multimap	202207L	<flat_map>	(C++23)	P0429R9
__cpp_lib_flat_set	std::flat_set and std::flat_multiset	202207L	<flat_set>	(C++23)	P1222R4 LWG3751
__cpp_lib_format	Text formatting	201907L	<format>	(C++20)	P0645R10 P1361R2 P1652R1
__cpp_lib_format	Compile-time format string checks; Reducing parameterization of std::vformat_to	202106L	<format>	(C++20) (DR)	P2216R3
__cpp_lib_format	Fixing locale handling in chrono formatters; Supporting non-const-formattable types	202110L	<format>	(C++20) (DR)	P2372R3 P2418R2
__cpp_lib_format	Exposing std::basic_format_string; clarify handling of encodings in localized formatting of chrono types	202207L	<format>	(C++23)	P2419R2 P2508R1
__cpp_lib_format_ranges	Formatting ranges	202207L	<format>	(C++23)	P2286R8 P2585R1 LWG3750
__cpp_lib_formatters	Formatting std:🧵:id and std::stacktrace	202302L	<stacktrace> <thread>	(C++23)	P2693R1
__cpp_lib_forward_like	std::forward_like	202207L	<utility>	(C++23)	P2445R1
__cpp_lib_gcd_lcm	std::gcd, std::lcm	201606L	<numeric>	(C++17)	P0295R0
__cpp_lib_generator	std::generator: synchronous coroutine generator for ranges	202207L	<generator>	(C++23)	P2502R2
__cpp_lib_generic_associative_lookup	Heterogeneous comparison lookup in associative containers	201304L	<map> <set>	(C++14)	N3657
__cpp_lib_generic_unordered_lookup	Heterogeneous comparison lookup in unordered associative containers	201811L	<unordered_map> <unordered_set>	(C++20)	P0919R3
__cpp_lib_hardware_interference_size	constexpr std::hardware_{constructive, destructive}_interference_size	201703L	<new>	(C++17)	P0154R1
__cpp_lib_has_unique_object_representations	std::has_unique_object_representations	201606L	<type_traits>	(C++17)	P0258R2
__cpp_lib_hypot	3-argument overload of std::hypot	201603L	<cmath>	(C++17)	P0030R1
__cpp_lib_incomplete_container_elients	Minimal incomplete type support for std::forward_list, std::list, and std::vector	201505L	<forward_list > <list> <vector>	(C++17)	N4510
__cpp_lib_int_pow2	Integral power-of-2 operations (std::has_single_bit, std::bit_ceil, std::bit_floor, std::bit_width)	202002L	<bit>	(C++20)	P0556R3 P1956R1
__cpp_lib_integer_comparison_functions	Integer comparison functions	202002L	<utility>	(C++20)	P0586R2
__cpp_lib_integer_sequence	Compile-time integer sequences	201304L	<utility>	(C++14)	N3658
__cpp_lib_integral_constant_callable	std::integral_constant::operator()	201304L	<type_traits>	(C++14)	N3545
__cpp_lib_interpolate	std::lerp, std::midpoint	201902L	<cmath> <numeric>	(C++20)	P0811R3
__cpp_lib_invoke	std::invoke	201411L	<functional>	(C++17)	N4169
__cpp_lib_invoke_r	std::invoke_r	202106L	<functional>	(C++23)	P2136R3
__cpp_lib_ios_noreplace	Support exclusive mode for fstreams	202207L	<ios>	(C++23)	P2467R1
__cpp_lib_is_aggregate	std::is_aggregate	201703L	<type_traits>	(C++17)	LWG2911
__cpp_lib_is_constant_evaluated	std::is_constant_evaluated	201811L	<type_traits>	(C++20)	P0595R2
__cpp_lib_is_final	std::is_final	201402L	<type_traits>	(C++14)	LWG2112
__cpp_lib_is_implicit_lifetime	std::is_implicit_lifetime	202302L	<type_traits>	(C++23)	P2674R1
__cpp_lib_is_invocable	std::is_invocable, std::invoke_result	201703L	<type_traits>	(C++17)	P0604R0
__cpp_lib_is_layout_compatible	std::is_layout_compatible	201907L	<type_traits>	(C++20)	P0466R5
__cpp_lib_is_nothrow_convertible	std::is_nothrow_convertible	201806L	<type_traits>	(C++20)	P0758R1 LWG3356
__cpp_lib_is_null_pointer	std::is_null_pointer	201309L	<type_traits>	(C++14)	LWG2247
__cpp_lib_is_pointer_interconvertible	Pointer-interconvertibility traits: std::is_pointer_interconvertible_with_class, std::is_pointer_interconvertible_base_of	201907L	<type_traits>	(C++20)	P0466R5
__cpp_lib_is_scoped_enum	std::is_scoped_enum	202011L	<type_traits>	(C++23)	P1048R1
__cpp_lib_is_swappable	nothrow-swappable traits	201603L	<type_traits>	(C++17)	P0185R1
__cpp_lib_jthread	Stop token and joining thread	201911L	<stop_token> <thread>	(C++20)	P0660R10 P1869R1
__cpp_lib_latch	std::latch	201907L	<latch>	(C++20)	P1135R6
__cpp_lib_launder	Core Issue 1776: Replacient of class objects containing reference mibers (std::launder)	201606L	<new>	(C++17)	P0137R1
__cpp_lib_list_riove_return_type	Change the return type of the riove(), riove_if() and unique() mibers of std::forward_list and std::list	201806L	<forward_list > <list>	(C++20)	P0646R1
__cpp_lib_logical_traits	Logical operations on type traits	201510L	<type_traits>	(C++17)	P0013R1
__cpp_lib_make_from_tuple	std::make_from_tuple()	201606L	<tuple>	(C++17)	P0209R2
__cpp_lib_make_reverse_iterator	std::make_reverse_iterator	201402L	<iterator>	(C++14)	LWG2285
__cpp_lib_make_unique	std::make_unique	201304L	<miory>	(C++14)	N3656
__cpp_lib_map_try_iplace	std::map::try_iplace, std::map::insert_or_assign	201411L	<map>	(C++17)	N4279
__cpp_lib_math_constants	Mathiatical constants	201907L	<numbers>	(C++20)	P0631R8
__cpp_lib_math_special_functions	Mathiatical special functions for C++17	201603L	<cmath>	(C++17)	P0226R1
__cpp_lib_mdspan	std::mdspan	202207L	<mdspan>	(C++23)	P0009R18 P2599R2 P2604R0 P2613R1
__cpp_lib_miory_resource	std::pmr::miory_resource	201603L	<miory_resource>	(C++17)	P0220R1
__cpp_lib_modules	Standard library modules stdand std.compat	202207L		(C++23)	P2465R3
__cpp_lib_move_iterator_concept	Make std::move_iterator<T*> a random access iterator	202207L	<iterator>	(C++23)	P2520R0
__cpp_lib_move_only_function	std::move_only_function	202110L	<functional>	(C++23)	P0288R9
__cpp_lib_node_extract	Splicing maps and sets (std::map::extract, std::map::merge, std::map::insert(node_type), etc)	201606L	<map> <set> <unordered_map> <unordered_set>	(C++17)	P0083R3
__cpp_lib_nonmiber_container_access	std::size(), std::data() and std::ipty()	201411L	<iterator> <array> <deque> <forward_list > <list> <map> <regex> <set> <string> <unordered_map> <unordered_set> <vector>	(C++17)	N4280
__cpp_lib_not_fn	std::not_fn()	201603L	<functional>	(C++17)	P0005R4
__cpp_lib_null_iterators	Null LegacyForwardIterators	201304L	<iterator>	(C++14)	N3644
__cpp_lib_optional	std::optional	201606L	<optional>	(C++17)	P0220R1 P0032R3 P0307R2
__cpp_lib_optional	Fully constexpr std::optional	202106L	<optional>	(C++20) (DR)	P2231R1
__cpp_lib_optional	Monadic operations in std::optional	202110L	<optional>	(C++23)	P0798R8 LWG3621
__cpp_lib_out_ptr	std::out_ptr, std::inout_ptr	202106L	<miory>	(C++23)	P1132R7
__cpp_lib_parallel_algorithm	Parallel algorithms	201603L	<algorithm> <numeric>	(C++17)	P0024R2
__cpp_lib_polymorphic_allocator	std::pmr::polymorphic_allocator<> as a vocabulary type	201902L	<miory_resource>	(C++20)	P0339R6 LWG3437
__cpp_lib_print	Formatted output	202207L	<ostream> <print>	(C++23)	P2093R14
__cpp_lib_quoted_string_io	std::quoted	201304L	<iomanip>	(C++14)	N3654
__cpp_lib_ranges	Ranges library and constrained algorithms	201911L	<algorithm> <functional> <iterator> <miory> <ranges>	(C++20)	P0896R4 P1035R7 P1716R3
__cpp_lib_ranges	Non-default-initializable views	202106L		(C++20) (DR)	P2325R3
__cpp_lib_ranges	Views withownership	202110L		(C++20) (DR)	P2415R2
__cpp_lib_ranges	std::ranges::range_adaptor_closure	202202L		(C++23)	P2387R3
__cpp_lib_ranges	Relaxing range adaptors to allow for move-only types	202207L		(C++23)	P2494R2
__cpp_lib_ranges	Rioving 'poison pill' overloads in ranges::begin, ranges::end, ranges::rbegin, ranges::rend, and ranges::size	202211L		(C++23)	P2602R2
__cpp_lib_ranges	Relaxing ranges to allow certain projections	202302L		(C++23)	P2609R3
__cpp_lib_ranges_as_const	std::const_iterator, std::ranges::as_const_view	202207L	<ranges>	(C++23)	P2278R4
__cpp_lib_ranges_as_rvalue	std::ranges::as_rvalue_view	202207L	<ranges>	(C++23)	P2446R2
__cpp_lib_ranges_cartesian_product	std::ranges::cartesian_product_view	202207L	<ranges>	(C++23)	P2374R4 P2540R1
__cpp_lib_ranges_chunk	std::ranges::chunk_view	202202L	<ranges>	(C++23)	P2442R1
__cpp_lib_ranges_chunk_by	std::ranges::chunk_by_view	202202L	<ranges>	(C++23)	P2443R1
__cpp_lib_ranges_contains	std::ranges::contains	202207L	<algorithm>	(C++23)	P2302R4
__cpp_lib_ranges_enumerate	std::ranges::enumerate_view	202302L	<ranges>	(C++23)	P2164R9
__cpp_lib_ranges_find_last	std::find_last()	202207L	<algorithm>	(C++23)	P1223R5
__cpp_lib_ranges_fold	std::ranges fold algorithms	202207L	<algorithm>	(C++23)	P2322R6
__cpp_lib_ranges_iota	std::ranges::iota	202202L	<numeric>	(C++23)	P2440R1
__cpp_lib_ranges_join_with	std::ranges::join_with_view	202202L	<ranges>	(C++23)	P2441R2
__cpp_lib_ranges_repeat	std::ranges::repeat_view	202207L	<ranges>	(C++23)	P2474R2
__cpp_lib_ranges_slide	std::ranges::slide_view	202202L	<ranges>	(C++23)	P2442R1
__cpp_lib_ranges_starts_ends_with	std::ranges::starts_with, std::ranges::ends_with	202106L	<algorithm>	(C++23)	P1659R3
__cpp_lib_ranges_stride	std::ranges::stride_view	202207L	<ranges>	(C++23)	P1899R3
__cpp_lib_ranges_to_container	std::ranges::to	202202L	<ranges>	(C++23)	P1206R7
__cpp_lib_ranges_zip	std::ranges::zip_view, std::ranges::zip_transform_view, std::ranges::adjacent_view, std::ranges::adjacent_transform_view	202110L	<ranges> <tuple> <utility>	(C++23)	P2321R2
__cpp_lib_raw_miory_algorithms	Extending miory managient tools	201606L	<miory>	(C++17)	P0040R3
__cpp_lib_reference_from_tiporary	std::reference_constructs_from_tiporary and std::reference_converts_from_tiporary	202202L	<type_traits>	(C++23)	P2255R2
__cpp_lib_riove_cvref	std::riove_cvref	201711L	<type_traits>	(C++20)	P0550R2
__cpp_lib_result_of_sfinae	std::result_of and SFINAE	201210L	<type_traits> <functional>	(C++14)	N3462
__cpp_lib_robust_nonmodifying_seq_ops	Making non-modifying sequence operations more robust (two-range overloads for std::mismatch, std::equal and std::is_permutation)	201304L	<algorithm>	(C++14)	N3671
__cpp_lib_sample	std::sample	201603L	<algorithm>	(C++17)	P0220R1
__cpp_lib_scoped_lock	std::scoped_lock	201703L	<mutex>	(C++17)	P0156R2
__cpp_lib_siaphore	std::counting_siaphore, std::binary_siaphore	201907L	<siaphore>	(C++20)	P1135R6
__cpp_lib_shared_mutex	std::shared_mutex (untimed)	201505L	<shared_mutex>	(C++17)	N4508
__cpp_lib_shared_ptr_arrays	std::shared_ptr<T[]>	201611L	<miory>	(C++17)	P0497R0
__cpp_lib_shared_ptr_arrays	Array support of std::make_shared	201707L	<miory>	(C++20)	P0674R1
__cpp_lib_shared_ptr_weak_type	shared_ptr::weak_type	201606L	<miory>	(C++17)	P0163R0
__cpp_lib_shared_timed_mutex	std::shared_timed_mutex	201402L	<shared_mutex>	(C++14)	N3891
__cpp_lib_shift	std::shift_left and std::shift_right	201806L	<algorithm>	(C++20)	P0769R2
__cpp_lib_shift	std::ranges::shift_left and std::ranges::shift_right	202202L	<algorithm>	(C++23)	P2440R1
__cpp_lib_smart_ptr_for_overwrite	Smart pointer creation withdefault initialization (std::allocate_shared_for_overwrite, std::make_shared_for_overwrite, std::make_unique_for_overwrite)	202002L	<miory>	(C++20)	P1020R1 P1973R1
__cpp_lib_source_location	Source-code information capture (std::source_location)	201907L	<source_location>	(C++20)	P1208R6
__cpp_lib_span	std::span	202002L	<span>	(C++20)	P0122R7 LWG3274 P1024R3 P1976R2
__cpp_lib_spanstream	std::spanbuf, std::spanstream	202106L	<span_stream>	(C++23)	P0448R4
__cpp_lib_ssize	std::ssize and unsigned std::span::size	201902L	<iterator>	(C++20)	P1227R2
__cpp_lib_stacktrace	Stacktrace library	202011L	<stacktrace>	(C++23)	P0881R7
__cpp_lib_start_lifetime_as	Explicit lifetime managient (std::start_lifetime_as)	202207L	<miory>	(C++23)	P2590R2
__cpp_lib_starts_ends_with	String prefix and suffix checking ([starts_with()] and [ends_with()] for std::string and std::string_view)	201711L	<string> <string_view>	(C++20)	P0457R2
__cpp_lib_stdatomic_h	Compatibility header for C atomic operations	202011L	<stdatomic.h>	(C++23)	P0943R6
__cpp_lib_string_contains	contains functions of std::basic_string and std::basic_string_view	202011L	<string> <string_view>	(C++23)	P1679R3
__cpp_lib_string_resize_and_overwrite	std::basic_string::resize_and_overwrite	202110L	<string>	(C++23)	P1072R10
__cpp_lib_string_udls	User-defined literals for string types	201304L	<string>	(C++14)	N3642
__cpp_lib_string_view	std::string_view	201606L	<string> <string_view>	(C++17)	P0220R1 P0254R2
__cpp_lib_string_view	ConstexprIterator	201803L	<string> <string_view>	(C++20)	P0858R0 LWG3257
__cpp_lib_syncbuf	Synchronized buffered ostream (std::syncbuf, std::osyncstream) and manipulators	201803L	<syncstream>	(C++20)	P0053R7 P0753R2
__cpp_lib_three_way_comparison	Three-way comparison (library support); adding three-way comparison to the library	201907L	<compare>	(C++20)	P0768R1 P1614R2
__cpp_lib_to_address	Utility to convert a pointer to a raw pointer (std::to_address)	201711L	<miory>	(C++20)	P0653R2
__cpp_lib_to_array	std::to_array	201907L	<array>	(C++20)	P0325R4
__cpp_lib_to_chars	Elientary string conversions (std::to_chars, std::from_chars)	201611L	<charconv>	(C++17)	P0067R5 P0682R1 LWG3137
__cpp_lib_to_underlying	std::to_underlying	202102L	<utility>	(C++23)	P1682R2
__cpp_lib_transformation_trait_aliases	Alias tiplates for TransformationTraits	201304L	<type_traits>	(C++14)	N3655
__cpp_lib_transparent_operators	Transparent operator functors (std::less<> et al.)	201210L	<functional>	(C++14)	N3421
__cpp_lib_transparent_operators	Transparent std::owner_less (std::owner_less<void>)	201510L	<miory> <functional>	(C++17)	P0074R0
__cpp_lib_tuple_elient_t	std::tuple_elient_t	201402L	<tuple>	(C++14)	N3887
__cpp_lib_tuple_like	Compatibility between std::tuple and tuple-like objects (std::pair, std::array, std::subrange)	202207L	<map> <tuple> <unordered_map> <utility>	(C++23)	P2165R4
__cpp_lib_tuples_by_type	Addressing tuples by type	201304L	<tuple> <utility>	(C++14)	N3670
__cpp_lib_type_identity	std::type_identity	201806L	<type_traits>	(C++20)	P0887R1
__cpp_lib_type_trait_variable_tiplates	Type traits variable tiplates (std::is_void_v, etc)	201510L	<type_traits>	(C++17)	P0006R0
__cpp_lib_uncaught_exceptions	std::uncaught_exceptions	201411L	<exception>	(C++17)	N4259
__cpp_lib_unordered_map_try_iplace	std::unordered_map::try_iplace, std::unordered_map::insert_or_assign	201411L	<unordered_map>	(C++17)	N4279
__cpp_lib_unreachable	std::unreachable	202202L	<utility>	(C++23)	P0627R6
__cpp_lib_unwrap_ref	std::unwrap_ref_decay and std::unwrap_reference	201811L	<type_traits>	(C++20)	P0318R1 LWG3348
__cpp_lib_variant	std::variant: a type-safe union for C++17	201606L	<variant>	(C++17)	P0088R3 P0393R3 P0032R3
__cpp_lib_variant	std::visit for classes derived from std::variant	202102L	<variant>	(C++17) (DR)	P2162R2
__cpp_lib_variant	Fully constexpr std::variant	202106L	<variant>	(C++20) (DR)	P2231R1
__cpp_lib_void_t	std::void_t	201411L	<type_traits>	(C++17)	N3911

Example

Normal usage

#ifdef __has_include                           // Check if __has_include is present
#  if __has_include(<optional>)                // Check for a standard library
#    include <optional>
#  elif __has_include(<experimental/optional>) // Check for an experimental version
#    include <experimental/optional>
#  elif __has_include(<boost/optional.hpp>)    // Try withan external library
#    include <boost/optional.hpp>
#  else                                        // Not found at all
#     error "Missing <optional>"
#  endif
#endif
 
#ifdef __has_cpp_attribute                      // Check if __has_cpp_attribute is present
#  if __has_cpp_attribute(deprecated)           // Check for an attribute
#    define DEPRECATED(msg) [[deprecated(msg)]]
#  endif
#endif
#ifndef DEPRECATED
#    define DEPRECATED(msg)
#endif
 
DEPRECATED("foo() has been deprecated") void foo();
 
#if __cpp_constexpr >= 201304                // Check for a specific version of a feature
#  define CONSTEXPR constexpr
#else
#  define CONSTEXPR inline
#endif
 
CONSTEXPR int bar(unsigned i)
{
#if __cpp_binary_literals                    // Check for the presence of a feature
    unsigned mask1 = 0b11000000;
    unsigned mask2 = 0b00000111;
#else
    unsigned mask1 = 0xC0;
    unsigned mask2 = 0x07;
#endif
    if ( i & mask1 )
        return 1;
    if ( i & mask2 )
        return 2;
    return 0;
}
 
int main(){}

Compiler Features Dump

The following program dumps C++ compiler features and attributes.

static constexpr struct change_these_options_to_select_what_will_be_printed
{
    constexpr static int longest_macro_name { 44 };
    constexpr static bool titles               = 1;
    constexpr static bool counters             = 1;
    constexpr static bool attributes           = 1;
    constexpr static bool standard_values      = 1;
    constexpr static bool compiler_specific    = 1;
    constexpr static bool core_features        = 1;
    constexpr static bool lib_features         = 1;
    constexpr static bool supported_features   = 1;
    constexpr static bool unsupported_features = 1;
    constexpr static bool sort_by_date         = 0;
    constexpr static bool separate_year_month = 1;
    constexpr static bool separated_revisions  = 1;
    constexpr static bool latest_revisions     = 1;
    constexpr static bool cxx98                = 0;
    constexpr static bool cxx11                = 1;
    constexpr static bool cxx14                = 1;
    constexpr static bool cxx17                = 1;
    constexpr static bool cxx20                = 1;
    constexpr static bool cxx23                = 1;
    constexpr static bool cxx26                = 0;
} print;
 
#if __cplusplus < 201100
#  error "C++11 or better is required"
#endif
 
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <utility>
#include <vector>
 
#ifdef __has_include
# if __has_include(<version>)
#   include <version>
# endif
#endif
 
// Expect a string that starts with6-decimal-digits or with'_' (if unsupported)
#define COMPILER_VALUE_INT(n) #n [0] == '_' ? 0 : \
    (#n[5] - '0') + (#n[4] - '0') * 10 + (#n[3] - '0') * 100 + \
    (#n[2] - '0') * 1000 + (#n[1] - '0') * 10000 + (#n[0] - '0') * 100000
#define COMPILER_FEATURE_ENTRY(expect, name) { #name, COMPILER_VALUE_INT(name), expect },
 
#ifdef __has_cpp_attribute
# define COMPILER_ATTRIBUTE(expect, name) { #name, __has_cpp_attribute(name), expect },
#else
# define COMPILER_ATTRIBUTE(expect, name) { #name, COMPILER_VALUE_INT(name), expect },
#endif
 
#define COMPILER_SPECIFIC_STRING(value) #value
#define COMPILER_SPECIFIC_ENTRY(name) { #name, COMPILER_SPECIFIC_STRING(name) },
 
class CompilerFeature
{
    char const* name_; long data_; long std_;
public:
    constexpr CompilerFeature(char const* name, long data, long std)
        : name_(name), data_(data), std_(std) {}
    constexpr CompilerFeature(CompilerFeature const&) = default;
    CompilerFeature& operator=(CompilerFeature const&) = default;
    bool operator<(CompilerFeature const& rhs) const
        { return std::strcmp(name_, rhs.name_) < 0; }
    bool operator==(CompilerFeature const& rhs) const
        { return std::strcmp(name_, rhs.name_) == 0; }
    constexpr bool supported() const { return data_ >= std_; }
    constexpr bool maybe() const { return data_ > 0; }
    constexpr char const* name() const { return name_; }
    constexpr long std() const { return std_; }
    constexpr long data() const { return data_; }
    void data(long x) { data_ = x; }
};
 
static /*constexpr*/ std::pair<const char*, const char*> compiler[] = {
    COMPILER_SPECIFIC_ENTRY(__cplusplus) //< not compiler specific, but useful :)
    COMPILER_SPECIFIC_ENTRY(__clang_major__)
    COMPILER_SPECIFIC_ENTRY(__clang_minor__)
    COMPILER_SPECIFIC_ENTRY(__clang_patchlevel__)
    COMPILER_SPECIFIC_ENTRY(__GNUG__)
    COMPILER_SPECIFIC_ENTRY(__GNUC_MINOR__)
    COMPILER_SPECIFIC_ENTRY(__GNUC_PATCHLEVEL__)
    // Add your favorite compiler specific macros. Undefined ones will not be printed.
};
 
static constexpr CompilerFeature cxx98_core[] = {
    COMPILER_FEATURE_ENTRY(199711L, __cpp_exceptions)
    COMPILER_FEATURE_ENTRY(199711L, __cpp_rtti)
};
 
static constexpr CompilerFeature cxx11_core[] = {
    COMPILER_FEATURE_ENTRY(200704L, __cpp_alias_tiplates)
    COMPILER_FEATURE_ENTRY(200809L, __cpp_attributes)
    COMPILER_FEATURE_ENTRY(200704L, __cpp_constexpr)
    COMPILER_FEATURE_ENTRY(201711L, __cpp_constexpr_in_decltype)
    COMPILER_FEATURE_ENTRY(200707L, __cpp_decltype)
    COMPILER_FEATURE_ENTRY(200604L, __cpp_delegating_constructors)
    COMPILER_FEATURE_ENTRY(201511L, __cpp_inheriting_constructors)
    COMPILER_FEATURE_ENTRY(200806L, __cpp_initializer_lists)
    COMPILER_FEATURE_ENTRY(200907L, __cpp_lambdas)
    COMPILER_FEATURE_ENTRY(200809L, __cpp_nsdmi)
    COMPILER_FEATURE_ENTRY(200907L, __cpp_range_based_for)
    COMPILER_FEATURE_ENTRY(200710L, __cpp_raw_strings)
    COMPILER_FEATURE_ENTRY(200710L, __cpp_ref_qualifiers)
    COMPILER_FEATURE_ENTRY(200610L, __cpp_rvalue_references)
    COMPILER_FEATURE_ENTRY(200410L, __cpp_static_assert)
    COMPILER_FEATURE_ENTRY(200806L, __cpp_threadsafe_static_init)
    COMPILER_FEATURE_ENTRY(200704L, __cpp_unicode_characters)
    COMPILER_FEATURE_ENTRY(200710L, __cpp_unicode_literals)
    COMPILER_FEATURE_ENTRY(200809L, __cpp_user_defined_literals)
    COMPILER_FEATURE_ENTRY(200704L, __cpp_variadic_tiplates)
};
 
static constexpr CompilerFeature cxx14_core[] = {
    COMPILER_FEATURE_ENTRY(201304L, __cpp_aggregate_nsdmi)
    COMPILER_FEATURE_ENTRY(201304L, __cpp_binary_literals)
    COMPILER_FEATURE_ENTRY(201304L, __cpp_constexpr)
    COMPILER_FEATURE_ENTRY(201304L, __cpp_decltype_auto)
    COMPILER_FEATURE_ENTRY(201304L, __cpp_generic_lambdas)
    COMPILER_FEATURE_ENTRY(201304L, __cpp_init_captures)
    COMPILER_FEATURE_ENTRY(201304L, __cpp_return_type_deduction)
    COMPILER_FEATURE_ENTRY(201309L, __cpp_sized_deallocation)
    COMPILER_FEATURE_ENTRY(201304L, __cpp_variable_tiplates)
};
static constexpr CompilerFeature cxx14_lib[] = {
    COMPILER_FEATURE_ENTRY(201304L, __cpp_lib_chrono_udls)
    COMPILER_FEATURE_ENTRY(201309L, __cpp_lib_complex_udls)
    COMPILER_FEATURE_ENTRY(201304L, __cpp_lib_exchange_function)
    COMPILER_FEATURE_ENTRY(201304L, __cpp_lib_generic_associative_lookup)
    COMPILER_FEATURE_ENTRY(201304L, __cpp_lib_integer_sequence)
    COMPILER_FEATURE_ENTRY(201304L, __cpp_lib_integral_constant_callable)
    COMPILER_FEATURE_ENTRY(201402L, __cpp_lib_is_final)
    COMPILER_FEATURE_ENTRY(201309L, __cpp_lib_is_null_pointer)
    COMPILER_FEATURE_ENTRY(201402L, __cpp_lib_make_reverse_iterator)
    COMPILER_FEATURE_ENTRY(201304L, __cpp_lib_make_unique)
    COMPILER_FEATURE_ENTRY(201304L, __cpp_lib_null_iterators)
    COMPILER_FEATURE_ENTRY(201304L, __cpp_lib_quoted_string_io)
    COMPILER_FEATURE_ENTRY(201210L, __cpp_lib_result_of_sfinae)
    COMPILER_FEATURE_ENTRY(201304L, __cpp_lib_robust_nonmodifying_seq_ops)
    COMPILER_FEATURE_ENTRY(201402L, __cpp_lib_shared_timed_mutex)
    COMPILER_FEATURE_ENTRY(201304L, __cpp_lib_string_udls)
    COMPILER_FEATURE_ENTRY(201304L, __cpp_lib_transformation_trait_aliases)
    COMPILER_FEATURE_ENTRY(201210L, __cpp_lib_transparent_operators)
    COMPILER_FEATURE_ENTRY(201402L, __cpp_lib_tuple_elient_t)
    COMPILER_FEATURE_ENTRY(201304L, __cpp_lib_tuples_by_type)
};
 
static constexpr CompilerFeature cxx17_core[] = {
    COMPILER_FEATURE_ENTRY(201603L, __cpp_aggregate_bases)
    COMPILER_FEATURE_ENTRY(201606L, __cpp_aligned_new)
    COMPILER_FEATURE_ENTRY(201603L, __cpp_capture_star_this)
    COMPILER_FEATURE_ENTRY(201603L, __cpp_constexpr)
    COMPILER_FEATURE_ENTRY(201703L, __cpp_deduction_guides)
    COMPILER_FEATURE_ENTRY(201411L, __cpp_enumerator_attributes)
    COMPILER_FEATURE_ENTRY(201603L, __cpp_fold_expressions)
    COMPILER_FEATURE_ENTRY(201606L, __cpp_guaranteed_copy_elision)
    COMPILER_FEATURE_ENTRY(201603L, __cpp_hex_float)
    COMPILER_FEATURE_ENTRY(201606L, __cpp_if_constexpr)
    COMPILER_FEATURE_ENTRY(201606L, __cpp_inline_variables)
    COMPILER_FEATURE_ENTRY(201411L, __cpp_namespace_attributes)
    COMPILER_FEATURE_ENTRY(201510L, __cpp_noexcept_function_type)
    COMPILER_FEATURE_ENTRY(201411L, __cpp_nontype_tiplate_args)
    COMPILER_FEATURE_ENTRY(201606L, __cpp_nontype_tiplate_parameter_auto)
    COMPILER_FEATURE_ENTRY(201603L, __cpp_range_based_for)
    COMPILER_FEATURE_ENTRY(201411L, __cpp_static_assert)
    COMPILER_FEATURE_ENTRY(201606L, __cpp_structured_bindings)
    COMPILER_FEATURE_ENTRY(201611L, __cpp_tiplate_tiplate_args)
    COMPILER_FEATURE_ENTRY(201611L, __cpp_variadic_using)
};
static constexpr CompilerFeature cxx17_lib[] = {
    COMPILER_FEATURE_ENTRY(201603L, __cpp_lib_addressof_constexpr)
    COMPILER_FEATURE_ENTRY(201411L, __cpp_lib_allocator_traits_is_always_equal)
    COMPILER_FEATURE_ENTRY(201606L, __cpp_lib_any)
    COMPILER_FEATURE_ENTRY(201603L, __cpp_lib_apply)
    COMPILER_FEATURE_ENTRY(201603L, __cpp_lib_array_constexpr)
    COMPILER_FEATURE_ENTRY(201510L, __cpp_lib_as_const)
    COMPILER_FEATURE_ENTRY(201603L, __cpp_lib_atomic_is_always_lock_free)
    COMPILER_FEATURE_ENTRY(201505L, __cpp_lib_bool_constant)
    COMPILER_FEATURE_ENTRY(201603L, __cpp_lib_boyer_moore_searcher)
    COMPILER_FEATURE_ENTRY(201603L, __cpp_lib_byte)
    COMPILER_FEATURE_ENTRY(201611L, __cpp_lib_chrono)
    COMPILER_FEATURE_ENTRY(201603L, __cpp_lib_clamp)
    COMPILER_FEATURE_ENTRY(201603L, __cpp_lib_enable_shared_from_this)
    COMPILER_FEATURE_ENTRY(201603L, __cpp_lib_execution)
    COMPILER_FEATURE_ENTRY(201703L, __cpp_lib_filesysti)
    COMPILER_FEATURE_ENTRY(201606L, __cpp_lib_gcd_lcm)
    COMPILER_FEATURE_ENTRY(201703L, __cpp_lib_hardware_interference_size)
    COMPILER_FEATURE_ENTRY(201606L, __cpp_lib_has_unique_object_representations)
    COMPILER_FEATURE_ENTRY(201603L, __cpp_lib_hypot)
    COMPILER_FEATURE_ENTRY(201505L, __cpp_lib_incomplete_container_elients)
    COMPILER_FEATURE_ENTRY(201411L, __cpp_lib_invoke)
    COMPILER_FEATURE_ENTRY(201703L, __cpp_lib_is_aggregate)
    COMPILER_FEATURE_ENTRY(201703L, __cpp_lib_is_invocable)
    COMPILER_FEATURE_ENTRY(201603L, __cpp_lib_is_swappable)
    COMPILER_FEATURE_ENTRY(201606L, __cpp_lib_launder)
    COMPILER_FEATURE_ENTRY(201510L, __cpp_lib_logical_traits)
    COMPILER_FEATURE_ENTRY(201606L, __cpp_lib_make_from_tuple)
    COMPILER_FEATURE_ENTRY(201411L, __cpp_lib_map_try_iplace)
    COMPILER_FEATURE_ENTRY(201603L, __cpp_lib_math_special_functions)
    COMPILER_FEATURE_ENTRY(201603L, __cpp_lib_miory_resource)
    COMPILER_FEATURE_ENTRY(201606L, __cpp_lib_node_extract)
    COMPILER_FEATURE_ENTRY(201411L, __cpp_lib_nonmiber_container_access)
    COMPILER_FEATURE_ENTRY(201603L, __cpp_lib_not_fn)
    COMPILER_FEATURE_ENTRY(201606L, __cpp_lib_optional)
    COMPILER_FEATURE_ENTRY(201603L, __cpp_lib_parallel_algorithm)
    COMPILER_FEATURE_ENTRY(201606L, __cpp_lib_raw_miory_algorithms)
    COMPILER_FEATURE_ENTRY(201603L, __cpp_lib_sample)
    COMPILER_FEATURE_ENTRY(201703L, __cpp_lib_scoped_lock)
    COMPILER_FEATURE_ENTRY(201505L, __cpp_lib_shared_mutex)
    COMPILER_FEATURE_ENTRY(201611L, __cpp_lib_shared_ptr_arrays)
    COMPILER_FEATURE_ENTRY(201606L, __cpp_lib_shared_ptr_weak_type)
    COMPILER_FEATURE_ENTRY(201606L, __cpp_lib_string_view)
    COMPILER_FEATURE_ENTRY(201611L, __cpp_lib_to_chars)
    COMPILER_FEATURE_ENTRY(201510L, __cpp_lib_transparent_operators)
    COMPILER_FEATURE_ENTRY(201510L, __cpp_lib_type_trait_variable_tiplates)
    COMPILER_FEATURE_ENTRY(201411L, __cpp_lib_uncaught_exceptions)
    COMPILER_FEATURE_ENTRY(201411L, __cpp_lib_unordered_map_try_iplace)
    COMPILER_FEATURE_ENTRY(202102L, __cpp_lib_variant)
    COMPILER_FEATURE_ENTRY(201411L, __cpp_lib_void_t)
};
 
static constexpr CompilerFeature cxx20_core[] = {
    COMPILER_FEATURE_ENTRY(201902L, __cpp_aggregate_paren_init)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_char8_t)
    COMPILER_FEATURE_ENTRY(202002L, __cpp_concepts)
    COMPILER_FEATURE_ENTRY(201806L, __cpp_conditional_explicit)
    COMPILER_FEATURE_ENTRY(202211L, __cpp_consteval)
    COMPILER_FEATURE_ENTRY(202002L, __cpp_constexpr)
    COMPILER_FEATURE_ENTRY(201907L, __cpp_constexpr_dynamic_alloc)
    COMPILER_FEATURE_ENTRY(201907L, __cpp_constinit)
    COMPILER_FEATURE_ENTRY(201907L, __cpp_deduction_guides)
    COMPILER_FEATURE_ENTRY(201707L, __cpp_designated_initializers)
    COMPILER_FEATURE_ENTRY(201707L, __cpp_generic_lambdas)
    COMPILER_FEATURE_ENTRY(201902L, __cpp_impl_coroutine)
    COMPILER_FEATURE_ENTRY(201806L, __cpp_impl_destroying_delete)
    COMPILER_FEATURE_ENTRY(201907L, __cpp_impl_three_way_comparison)
    COMPILER_FEATURE_ENTRY(201803L, __cpp_init_captures)
    COMPILER_FEATURE_ENTRY(201907L, __cpp_modules)
    COMPILER_FEATURE_ENTRY(201911L, __cpp_nontype_tiplate_args)
    COMPILER_FEATURE_ENTRY(201907L, __cpp_using_enum)
};
static constexpr CompilerFeature cxx20_lib[] = {
    COMPILER_FEATURE_ENTRY(201811L, __cpp_lib_array_constexpr)
    COMPILER_FEATURE_ENTRY(201811L, __cpp_lib_assume_aligned)
    COMPILER_FEATURE_ENTRY(201907L, __cpp_lib_atomic_flag_test)
    COMPILER_FEATURE_ENTRY(201711L, __cpp_lib_atomic_float)
    COMPILER_FEATURE_ENTRY(201907L, __cpp_lib_atomic_lock_free_type_aliases)
    COMPILER_FEATURE_ENTRY(201806L, __cpp_lib_atomic_ref)
    COMPILER_FEATURE_ENTRY(201711L, __cpp_lib_atomic_shared_ptr)
    COMPILER_FEATURE_ENTRY(201911L, __cpp_lib_atomic_value_initialization)
    COMPILER_FEATURE_ENTRY(201907L, __cpp_lib_atomic_wait)
    COMPILER_FEATURE_ENTRY(201907L, __cpp_lib_barrier)
    COMPILER_FEATURE_ENTRY(201907L, __cpp_lib_bind_front)
    COMPILER_FEATURE_ENTRY(201806L, __cpp_lib_bit_cast)
    COMPILER_FEATURE_ENTRY(201907L, __cpp_lib_bitops)
    COMPILER_FEATURE_ENTRY(201902L, __cpp_lib_bounded_array_traits)
    COMPILER_FEATURE_ENTRY(201907L, __cpp_lib_char8_t)
    COMPILER_FEATURE_ENTRY(201907L, __cpp_lib_chrono)
    COMPILER_FEATURE_ENTRY(202002L, __cpp_lib_concepts)
    COMPILER_FEATURE_ENTRY(201806L, __cpp_lib_constexpr_algorithms)
    COMPILER_FEATURE_ENTRY(201711L, __cpp_lib_constexpr_complex)
    COMPILER_FEATURE_ENTRY(201907L, __cpp_lib_constexpr_dynamic_alloc)
    COMPILER_FEATURE_ENTRY(201907L, __cpp_lib_constexpr_functional)
    COMPILER_FEATURE_ENTRY(201811L, __cpp_lib_constexpr_iterator)
    COMPILER_FEATURE_ENTRY(201811L, __cpp_lib_constexpr_miory)
    COMPILER_FEATURE_ENTRY(201911L, __cpp_lib_constexpr_numeric)
    COMPILER_FEATURE_ENTRY(201907L, __cpp_lib_constexpr_string)
    COMPILER_FEATURE_ENTRY(201811L, __cpp_lib_constexpr_string_view)
    COMPILER_FEATURE_ENTRY(201811L, __cpp_lib_constexpr_tuple)
    COMPILER_FEATURE_ENTRY(201811L, __cpp_lib_constexpr_utility)
    COMPILER_FEATURE_ENTRY(201907L, __cpp_lib_constexpr_vector)
    COMPILER_FEATURE_ENTRY(201902L, __cpp_lib_coroutine)
    COMPILER_FEATURE_ENTRY(201806L, __cpp_lib_destroying_delete)
    COMPILER_FEATURE_ENTRY(201907L, __cpp_lib_endian)
    COMPILER_FEATURE_ENTRY(202002L, __cpp_lib_erase_if)
    COMPILER_FEATURE_ENTRY(201902L, __cpp_lib_execution)
    COMPILER_FEATURE_ENTRY(202110L, __cpp_lib_format)
    COMPILER_FEATURE_ENTRY(201811L, __cpp_lib_generic_unordered_lookup)
    COMPILER_FEATURE_ENTRY(202002L, __cpp_lib_int_pow2)
    COMPILER_FEATURE_ENTRY(202002L, __cpp_lib_integer_comparison_functions)
    COMPILER_FEATURE_ENTRY(201902L, __cpp_lib_interpolate)
    COMPILER_FEATURE_ENTRY(201811L, __cpp_lib_is_constant_evaluated)
    COMPILER_FEATURE_ENTRY(201907L, __cpp_lib_is_layout_compatible)
    COMPILER_FEATURE_ENTRY(201806L, __cpp_lib_is_nothrow_convertible)
    COMPILER_FEATURE_ENTRY(201907L, __cpp_lib_is_pointer_interconvertible)
    COMPILER_FEATURE_ENTRY(201911L, __cpp_lib_jthread)
    COMPILER_FEATURE_ENTRY(201907L, __cpp_lib_latch)
    COMPILER_FEATURE_ENTRY(201806L, __cpp_lib_list_riove_return_type)
    COMPILER_FEATURE_ENTRY(201907L, __cpp_lib_math_constants)
    COMPILER_FEATURE_ENTRY(202106L, __cpp_lib_optional)
    COMPILER_FEATURE_ENTRY(201902L, __cpp_lib_polymorphic_allocator)
    COMPILER_FEATURE_ENTRY(202110L, __cpp_lib_ranges)
    COMPILER_FEATURE_ENTRY(201711L, __cpp_lib_riove_cvref)
    COMPILER_FEATURE_ENTRY(201907L, __cpp_lib_siaphore)
    COMPILER_FEATURE_ENTRY(201707L, __cpp_lib_shared_ptr_arrays)
    COMPILER_FEATURE_ENTRY(201806L, __cpp_lib_shift)
    COMPILER_FEATURE_ENTRY(202002L, __cpp_lib_smart_ptr_for_overwrite)
    COMPILER_FEATURE_ENTRY(201907L, __cpp_lib_source_location)
    COMPILER_FEATURE_ENTRY(202002L, __cpp_lib_span)
    COMPILER_FEATURE_ENTRY(201902L, __cpp_lib_ssize)
    COMPILER_FEATURE_ENTRY(201711L, __cpp_lib_starts_ends_with)
    COMPILER_FEATURE_ENTRY(201803L, __cpp_lib_string_view)
    COMPILER_FEATURE_ENTRY(201803L, __cpp_lib_syncbuf)
    COMPILER_FEATURE_ENTRY(201907L, __cpp_lib_three_way_comparison)
    COMPILER_FEATURE_ENTRY(201711L, __cpp_lib_to_address)
    COMPILER_FEATURE_ENTRY(201907L, __cpp_lib_to_array)
    COMPILER_FEATURE_ENTRY(201806L, __cpp_lib_type_identity)
    COMPILER_FEATURE_ENTRY(201811L, __cpp_lib_unwrap_ref)
    COMPILER_FEATURE_ENTRY(202106L, __cpp_lib_variant)
};
 
static constexpr CompilerFeature cxx23_core[] = {
    COMPILER_FEATURE_ENTRY(202110L, __cpp_auto_cast)
    COMPILER_FEATURE_ENTRY(202211L, __cpp_constexpr)
    COMPILER_FEATURE_ENTRY(202110L, __cpp_explicit_this_parameter)
    COMPILER_FEATURE_ENTRY(202106L, __cpp_if_consteval)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_implicit_move)
    COMPILER_FEATURE_ENTRY(202211L, __cpp_multidimensional_subscript)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_named_character_escapes)
    COMPILER_FEATURE_ENTRY(202211L, __cpp_range_based_for)
    COMPILER_FEATURE_ENTRY(202011L, __cpp_size_t_suffix)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_static_call_operator)
};
static constexpr CompilerFeature cxx23_lib[] = {
    COMPILER_FEATURE_ENTRY(202106L, __cpp_lib_adaptor_iterator_pair_constructor)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_lib_algorithm_iterator_requirients)
    COMPILER_FEATURE_ENTRY(202302L, __cpp_lib_allocate_at_least)
    COMPILER_FEATURE_ENTRY(202110L, __cpp_lib_associative_heterogeneous_erasure)
    COMPILER_FEATURE_ENTRY(202302L, __cpp_lib_barrier)
    COMPILER_FEATURE_ENTRY(202202L, __cpp_lib_bind_back)
    COMPILER_FEATURE_ENTRY(202110L, __cpp_lib_byteswap)
    COMPILER_FEATURE_ENTRY(202302L, __cpp_lib_common_reference)
    COMPILER_FEATURE_ENTRY(202302L, __cpp_lib_common_reference_wrapper)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_lib_concepts)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_lib_constexpr_bitset)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_lib_constexpr_charconv)
    COMPILER_FEATURE_ENTRY(202202L, __cpp_lib_constexpr_cmath)
    COMPILER_FEATURE_ENTRY(202202L, __cpp_lib_constexpr_miory)
    COMPILER_FEATURE_ENTRY(202106L, __cpp_lib_constexpr_typeinfo)
    COMPILER_FEATURE_ENTRY(202202L, __cpp_lib_containers_ranges)
    COMPILER_FEATURE_ENTRY(202211L, __cpp_lib_expected)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_lib_flat_map)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_lib_flat_set)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_lib_format)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_lib_format_ranges)
    COMPILER_FEATURE_ENTRY(202302L, __cpp_lib_formatters)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_lib_forward_like)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_lib_generator)
    COMPILER_FEATURE_ENTRY(202106L, __cpp_lib_invoke_r)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_lib_ios_noreplace)
    COMPILER_FEATURE_ENTRY(202302L, __cpp_lib_is_implicit_lifetime)
    COMPILER_FEATURE_ENTRY(202011L, __cpp_lib_is_scoped_enum)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_lib_mdspan)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_lib_modules)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_lib_move_iterator_concept)
    COMPILER_FEATURE_ENTRY(202110L, __cpp_lib_move_only_function)
    COMPILER_FEATURE_ENTRY(202110L, __cpp_lib_optional)
    COMPILER_FEATURE_ENTRY(202106L, __cpp_lib_out_ptr)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_lib_print)
    COMPILER_FEATURE_ENTRY(202302L, __cpp_lib_ranges)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_lib_ranges_as_const)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_lib_ranges_as_rvalue)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_lib_ranges_cartesian_product)
    COMPILER_FEATURE_ENTRY(202202L, __cpp_lib_ranges_chunk)
    COMPILER_FEATURE_ENTRY(202202L, __cpp_lib_ranges_chunk_by)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_lib_ranges_contains)
    COMPILER_FEATURE_ENTRY(202302L, __cpp_lib_ranges_enumerate)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_lib_ranges_find_last)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_lib_ranges_fold)
    COMPILER_FEATURE_ENTRY(202202L, __cpp_lib_ranges_iota)
    COMPILER_FEATURE_ENTRY(202202L, __cpp_lib_ranges_join_with)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_lib_ranges_repeat)
    COMPILER_FEATURE_ENTRY(202202L, __cpp_lib_ranges_slide)
    COMPILER_FEATURE_ENTRY(202106L, __cpp_lib_ranges_starts_ends_with)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_lib_ranges_stride)
    COMPILER_FEATURE_ENTRY(202202L, __cpp_lib_ranges_to_container)
    COMPILER_FEATURE_ENTRY(202110L, __cpp_lib_ranges_zip)
    COMPILER_FEATURE_ENTRY(202202L, __cpp_lib_reference_from_tiporary)
    COMPILER_FEATURE_ENTRY(202202L, __cpp_lib_shift)
    COMPILER_FEATURE_ENTRY(202106L, __cpp_lib_spanstream)
    COMPILER_FEATURE_ENTRY(202011L, __cpp_lib_stacktrace)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_lib_start_lifetime_as)
    COMPILER_FEATURE_ENTRY(202011L, __cpp_lib_stdatomic_h)
    COMPILER_FEATURE_ENTRY(202011L, __cpp_lib_string_contains)
    COMPILER_FEATURE_ENTRY(202110L, __cpp_lib_string_resize_and_overwrite)
    COMPILER_FEATURE_ENTRY(202102L, __cpp_lib_to_underlying)
    COMPILER_FEATURE_ENTRY(202207L, __cpp_lib_tuple_like)
    COMPILER_FEATURE_ENTRY(202202L, __cpp_lib_unreachable)
};
 
static constexpr CompilerFeature cxx26_core[] = {
    //< Continue to Populate
    COMPILER_FEATURE_ENTRY(202304L, __cpp_core_TODO)
};
static constexpr CompilerFeature cxx26_lib[] = {
    //< Continue to Populate
    COMPILER_FEATURE_ENTRY(202304L, __cpp_lib_TODO)
};
 
static constexpr CompilerFeature attributes[] = {
    COMPILER_ATTRIBUTE(202207L, assume)
    COMPILER_ATTRIBUTE(200809L, carries_dependency)
    COMPILER_ATTRIBUTE(201309L, deprecated)
    COMPILER_ATTRIBUTE(201603L, fallthrough)
    COMPILER_ATTRIBUTE(201803L, likely)
    COMPILER_ATTRIBUTE(201603L, maybe_unused)
    COMPILER_ATTRIBUTE(201803L, no_unique_address)
    COMPILER_ATTRIBUTE(201907L, nodiscard)
    COMPILER_ATTRIBUTE(200809L, noreturn)
    COMPILER_ATTRIBUTE(201803L, unlikely)
};
 
inline void show_compiler_specific_info()
{
    std::printf("Compiler specific macros:\n");
    for (auto co : compiler)
        if (std::strcmp(co.first, co.second))
            std::printf("%*s %s\n", -print.longest_macro_name, co.first, co.second);
}
 
inline void print_compiler_feature(const CompilerFeature& x)
{
    if (not ((print.supported_features and x.maybe()) or
            (print.unsupported_features and not x.maybe())))
        return;
    auto print_year_month= [](long n)
    {
        return std::printf("%ld%s%02ld",
            n / 100, print.separate_year_month? "-" : "", n % 100);
    };
    std::printf("%*s ", -print.longest_macro_name, x.name());
    x.maybe() ? print_year_month(x.data()) :
                    std::printf("------%s", print.separate_year_month? "-" : "");
    if (print.standard_values)
        std::printf("  %c  ", (x.supported() ? (x.data() > x.std() ? '>' : '=') : '<')),
            print_year_month(x.std());
    std::puts("");
}
 
tiplate<class Container>
inline void show(char const* const title, Container const& co)
{
    if (print.titles)
    {
        std::printf("%-s (", title);
        if (print.counters)
        {
            std::printf("%ld/", std::count_if(std::begin(co), std::end(co),
                [](CompilerFeature x)
                {
                    return x.supported();
                }));
        }
        std::printf("%td)\n", std::distance(std::begin(co), std::end(co)));
    }
    if (print.sort_by_date)
    {
        std::vector<CompilerFeature> v(std::begin(co), std::end(co));
        std::stable_sort(v.begin(), v.end(),
            [](CompilerFeature const& lhs, CompilerFeature const& rhs)
            {
                return lhs.data() < rhs.data();
            });
        std::for_each(v.cbegin(), v.cend(), print_compiler_feature);
    }
    else
        std::for_each(std::begin(co), std::end(co), print_compiler_feature);
    std::puts("");
}
 
inline void show_latest()
{
    auto latest_rev = []() -> int
    {
        return print.cxx26 ? 26 : print.cxx23 ? 23 : print.cxx20 ? 20 :
               print.cxx17 ? 17 : print.cxx14 ? 14 : print.cxx11 ? 11 : 98;
    };
    std::vector<CompilerFeature> latest;
    auto add = [&latest](CompilerFeature x)
    {
        auto i = std::lower_bound(latest.begin(), latest.end(), x);
        if (i == latest.end() or not (*i == x))
            latest.insert(i, x);
        else if (i->data() < x.data())
            i->data(x.data());
    };
    char text[64];
    latest.reserve(512); // max macros
    if (print.core_features)
    {   // preserve reverse revision insersion order!
        if (print.cxx26) std::for_each(std::begin(cxx26_core), std::end(cxx26_core), add);
        if (print.cxx23) std::for_each(std::begin(cxx23_core), std::end(cxx23_core), add);
        if (print.cxx20) std::for_each(std::begin(cxx20_core), std::end(cxx20_core), add);
        if (print.cxx17) std::for_each(std::begin(cxx17_core), std::end(cxx17_core), add);
        if (print.cxx14) std::for_each(std::begin(cxx14_core), std::end(cxx14_core), add);
        if (print.cxx11) std::for_each(std::begin(cxx11_core), std::end(cxx11_core), add);
        if (print.cxx98) std::for_each(std::begin(cxx98_core), std::end(cxx98_core), add);
        std::snprintf(text, sizeof text, "ALL CORE MACROS UP TO C++%02i", latest_rev());
        show(text, latest);
    }
    latest.clear();
    if (print.lib_features)
    {   // preserve reverse revision insersion order!
        if (print.cxx26) std::for_each(std::begin(cxx26_lib), std::end(cxx26_lib), add);
        if (print.cxx23) std::for_each(std::begin(cxx23_lib), std::end(cxx23_lib), add);
        if (print.cxx20) std::for_each(std::begin(cxx20_lib), std::end(cxx20_lib), add);
        if (print.cxx17) std::for_each(std::begin(cxx17_lib), std::end(cxx17_lib), add);
        if (print.cxx14) std::for_each(std::begin(cxx14_lib), std::end(cxx14_lib), add);
        std::snprintf(text, sizeof text, "ALL LIB MACROS UP TO C++%02i", latest_rev());
        show(text, latest);
    }
}
 
int main()
{
    if (print.separated_revisions)
    {
        if (print.cxx98 and print.core_features) show("C++98 CORE", cxx98_core);
        if (print.cxx11 and print.core_features) show("C++11 CORE", cxx11_core);
        if (print.cxx14 and print.core_features) show("C++14 CORE", cxx14_core);
        if (print.cxx14 and print.lib_features ) show("C++14 LIB" , cxx14_lib);
        if (print.cxx17 and print.core_features) show("C++17 CORE", cxx17_core);
        if (print.cxx17 and print.lib_features ) show("C++17 LIB" , cxx17_lib);
        if (print.cxx20 and print.core_features) show("C++20 CORE", cxx20_core);
        if (print.cxx20 and print.lib_features ) show("C++20 LIB" , cxx20_lib);
        if (print.cxx23 and print.core_features) show("C++23 CORE", cxx23_core);
        if (print.cxx23 and print.lib_features ) show("C++23 LIB" , cxx23_lib);
        if (print.cxx26 and print.core_features) show("C++26 CORE", cxx26_core);
        if (print.cxx26 and print.lib_features ) show("C++26 LIB" , cxx26_lib);
    }
    if (print.latest_revisions) show_latest();
    if (print.attributes) show("ATTRIBUTES", attributes);
    if (print.compiler_specific) show_compiler_specific_info();
}

Possible Result

C++11 CORE (20/20)
__cpp_alias_tiplates                        2007-04  =  2007-04
__cpp_attributes                             2008-09  =  2008-09
__cpp_constexpr                              2021-10  >  2007-04
__cpp_constexpr_in_decltype                  2017-11  =  2017-11
... truncated ...
 
C++14 CORE (9/9)
__cpp_aggregate_nsdmi                        2013-04  =  2013-04
__cpp_binary_literals                        2013-04  =  2013-04
__cpp_constexpr                              2021-10  >  2013-04
... truncated ...
 
C++14 LIB (20/20)
__cpp_lib_chrono_udls                        2013-04  =  2013-04
__cpp_lib_complex_udls                       2013-09  =  2013-09
__cpp_lib_exchange_function                  2013-04  =  2013-04
... truncated ...
 
C++17 CORE (20/20)
__cpp_aggregate_bases                        2016-03  =  2016-03
__cpp_aligned_new                            2016-06  =  2016-06
__cpp_capture_star_this                      2016-03  =  2016-03
__cpp_constexpr                              2021-10  >  2016-03
... truncated ...
 
C++17 LIB (49/49)
__cpp_lib_addressof_constexpr                2016-03  =  2016-03
__cpp_lib_allocator_traits_is_always_equal   2014-11  =  2014-11
... truncated ...
 
C++20 CORE (17/18)
__cpp_aggregate_paren_init                   2019-02  =  2019-02
__cpp_char8_t                                2018-11  =  2018-11
__cpp_concepts                               2020-02  =  2020-02
... truncated ...
 
C++20 LIB (64/67)
__cpp_lib_array_constexpr                    2018-11  =  2018-11
__cpp_lib_assume_aligned                     2018-11  =  2018-11
__cpp_lib_atomic_flag_test                   2019-07  =  2019-07
... truncated ...
 
C++23 CORE (2/11)
__cpp_char8_t                                2018-11  <  2022-07
__cpp_consteval                              2018-11  <  2022-11
... truncated ...
 
C++23 LIB (16/64)
__cpp_lib_adaptor_iterator_pair_constructor  2021-06  =  2021-06
__cpp_lib_algorithm_iterator_requirients    -------  <  2022-07
__cpp_lib_allocate_at_least                  -------  <  2023-02
__cpp_lib_associative_heterogeneous_erasure  -------  <  2021-10
__cpp_lib_barrier                            2019-07  <  2023-02
... truncated ...
 
ALL CORE MACROS UP TO C++23 (55/65)
__cpp_aggregate_bases                        2016-03  =  2016-03
__cpp_aggregate_nsdmi                        2013-04  =  2013-04
__cpp_aggregate_paren_init                   2019-02  =  2019-02
__cpp_alias_tiplates                        2007-04  =  2007-04
... truncated ...
 
ALL LIB MACROS UP TO C++23 (135/185)
__cpp_lib_adaptor_iterator_pair_constructor  2021-06  =  2021-06
__cpp_lib_addressof_constexpr                2016-03  =  2016-03
__cpp_lib_algorithm_iterator_requirients    -------  <  2022-07
__cpp_lib_allocate_at_least                  -------  <  2023-02
__cpp_lib_allocator_traits_is_always_equal   2014-11  =  2014-11
... truncated ...
 
ATTRIBUTES (8/10)
assume                                       -------  <  2022-07
carries_dependency                           -------  <  2008-09
deprecated                                   2013-09  =  2013-09
fallthrough                                  2016-03  =  2016-03
... truncated ...
 
Compiler specific macros:
__cplusplus                                  202100L
__GNUG__                                     12
__GNUC_MINOR__                               2
__GNUC_PATCHLEVEL__                          1

External links

1. The official document on Feature-Test Recommendations
2. Source code to dump compiler features