Library feature-test macros (since C++20) (original) (raw)

C++

Compiler support
Freestanding and hosted
Language
Standard library
Standard library headers
Named requirements
Feature test macros (C++20)
Language support library
Concepts library (C++20)
Diagnostics library
Memory management library
Metaprogramming library (C++11)
General utilities library
Containers library
Iterators library
Ranges library (C++20)
Algorithms library
Strings library
Text processing library
Numerics library
Date and time library
Input/output library
Filesystem library (C++17)
Concurrency support library (C++11)
Execution control library (C++26)
Technical specifications
Symbols index
External libraries

[edit]

Utilities library

Language support Type support (basic types, RTTI) Library feature-test macros (C++20) Program utilities Variadic functions initializer_list(C++11) is_constant_evaluated(C++20) is_within_lifetime(C++26) source_location(C++20) Coroutine support (C++20) Contract support (C++26) Three-way comparison three_way_comparablethree_way_comparable_with(C++20)(C++20) strong_ordering(C++20) weak_ordering(C++20) partial_ordering(C++20) common_comparison_category(C++20) compare_three_way_result(C++20) compare_three_way(C++20) strong_order(C++20) weak_order(C++20) partial_order(C++20) compare_strong_order_fallback(C++20) compare_weak_order_fallback(C++20) compare_partial_order_fallback(C++20) is_eqis_ltis_lteq(C++20)(C++20)(C++20) is_neqis_gtis_gteq(C++20)(C++20)(C++20) General utilities Function objects Bit manipulation (C++20) C-style bit manipulation (C++26) bitset hash(C++11) Relational operators (deprecated in C++20) rel_ops::operator!=rel_ops::operator>rel_ops::operator<=rel_ops::operator>= Integer comparison functions cmp_equalcmp_lesscmp_less_than(C++20)(C++20)(C++20) cmp_not_equalcmp_greatercmp_greater_than(C++20)(C++20)(C++20) in_range(C++20) Swap and type operations swap ranges::swap(C++20) exchange(C++14) declval(C++11) to_underlying(C++23) forward(C++11) forward_like(C++23) move(C++11) move_if_noexcept(C++11) as_const(C++17) Common vocabulary types pair tuple(C++11) optional(C++17) any(C++17) variant(C++17) tuple_size(C++11) tuple_element(C++11) apply(C++17) make_from_tuple(C++17) expected(C++23)

[edit]

Each of following macros is defined if the header or one of the corresponding headers specified in the table is included.

[edit]

Macro name Value Header Free-standing
__cpp_lib_adaptor_iterator_pair_constructor 202106L
__cpp_lib_addressof_constexpr 201603L Yes
__cpp_lib_algorithm_default_value_type 202403L <forward_list>
__cpp_lib_algorithm_iterator_requirements 202207L
__cpp_lib_aligned_accessor 202411L
__cpp_lib_allocate_at_least 202302L
__cpp_lib_allocator_traits_is_always_equal 201411L <scoped_allocator> <forward_list> <unordered_map> <unordered_set> Yes
__cpp_lib_any 201606L
__cpp_lib_apply 201603L Yes
__cpp_lib_array_constexpr 201811L
__cpp_lib_as_const 201510L Yes
__cpp_lib_associative_heterogeneous_erasure 202110L <unordered_map> <unordered_set>
__cpp_lib_associative_heterogeneous_insertion 202306L <unordered_map> <unordered_set>
__cpp_lib_assume_aligned 201811L Yes
__cpp_lib_atomic_flag_test 201907L Yes
__cpp_lib_atomic_float 201711L Yes
__cpp_lib_atomic_is_always_lock_free 201603L Yes
__cpp_lib_atomic_lock_free_type_aliases 201907L
__cpp_lib_atomic_min_max 202403L Yes
__cpp_lib_atomic_ref 202411L Yes
__cpp_lib_atomic_shared_ptr 201711L
__cpp_lib_atomic_value_initialization 201911L Yes
__cpp_lib_atomic_wait 201907L Yes
__cpp_lib_barrier 202302L
__cpp_lib_bind_back 202306L Yes
__cpp_lib_bind_front 202306L Yes
__cpp_lib_bit_cast 201806L Yes
__cpp_lib_bitops 201907L Yes
__cpp_lib_bitset 202306L
__cpp_lib_bool_constant 201505L <type_traits> Yes
__cpp_lib_bounded_array_traits 201902L <type_traits> Yes
__cpp_lib_boyer_moore_searcher 201603L
__cpp_lib_byte 201603L Yes
__cpp_lib_byteswap 202110L Yes
__cpp_lib_char8_t 201907L <string_view> Yes
__cpp_lib_chrono 202306L
__cpp_lib_chrono_udls 201304L
__cpp_lib_clamp 201603L
__cpp_lib_common_reference 202302L <type_traits> Yes
__cpp_lib_common_reference_wrapper 202302L Yes
__cpp_lib_complex_udls 201309L
__cpp_lib_concepts 202207L Yes
__cpp_lib_constexpr_algorithms 202306L
__cpp_lib_constexpr_atomic 202411L
__cpp_lib_constexpr_bitset 202207L
__cpp_lib_constexpr_charconv 202207L Yes
__cpp_lib_constexpr_cmath 202306L
__cpp_lib_constexpr_complex 202306L
__cpp_lib_constexpr_deque 202502L
__cpp_lib_constexpr_dynamic_alloc 201907L
__cpp_lib_constexpr_exceptions 202502L
__cpp_lib_constexpr_flat_map 202502L <flat_map>
__cpp_lib_constexpr_flat_set 202502L <flat_set>
__cpp_lib_constexpr_forward_list 202502L <forward_list>
__cpp_lib_constexpr_functional 201907L Yes
__cpp_lib_constexpr_inplace_vector 202502L <inplace_vector>
__cpp_lib_constexpr_iterator 201811L Yes
__cpp_lib_constexpr_list 202502L
__cpp_lib_constexpr_map 202502L
__cpp_lib_constexpr_memory 202202L Yes
__cpp_lib_constexpr_new 202406L Yes
__cpp_lib_constexpr_numeric 201911L
__cpp_lib_constexpr_queue 202502L
__cpp_lib_constexpr_set 202502L
__cpp_lib_constexpr_stack 202502L
__cpp_lib_constexpr_string 201907L
__cpp_lib_constexpr_string_view 201811L <string_view>
__cpp_lib_constexpr_tuple 201811L Yes
__cpp_lib_constexpr_typeinfo 202106L Yes
__cpp_lib_constexpr_unordered_map 202502L <unordered_map>
__cpp_lib_constexpr_unordered_set 202502L <unordered_set>
__cpp_lib_constexpr_utility 201811L Yes
__cpp_lib_constexpr_vector 201907L
__cpp_lib_constrained_equality 202411L Yes
__cpp_lib_containers_ranges 202202L <forward_list> <unordered_map> <unordered_set>
__cpp_lib_contracts 202502L Yes
__cpp_lib_copyable_function 202306L
__cpp_lib_coroutine 201902L Yes
__cpp_lib_debugging 202403L Yes
__cpp_lib_destroying_delete 201806L Yes
__cpp_lib_enable_shared_from_this 201603L
__cpp_lib_endian 201907L Yes
__cpp_lib_erase_if 202002L <forward_list> <unordered_map> <unordered_set>
__cpp_lib_exchange_function 201304L Yes
__cpp_lib_execution 201902L
__cpp_lib_expected 202211L
__cpp_lib_filesystem 201703L
__cpp_lib_flat_map 202207L <flat_map>
__cpp_lib_flat_set 202207L <flat_set>
__cpp_lib_format 202311L
__cpp_lib_format_ranges 202207L
__cpp_lib_format_path 202403L
__cpp_lib_format_uchar 202311L
__cpp_lib_formatters 202302L
__cpp_lib_forward_like 202207L Yes
__cpp_lib_freestanding_algorithm 202502L Yes
__cpp_lib_freestanding_array 202311L Yes
__cpp_lib_freestanding_char_traits 202306L Yes
__cpp_lib_freestanding_charconv 202306L Yes
__cpp_lib_freestanding_cstdlib 202306L Yes
__cpp_lib_freestanding_cstring 202311L Yes
__cpp_lib_freestanding_cwchar 202306L Yes
__cpp_lib_freestanding_errc 202306L <system_error> Yes
__cpp_lib_freestanding_execution 202502L Yes
__cpp_lib_freestanding_expected 202311L Yes
__cpp_lib_freestanding_feature_test_macros 202306L Yes
__cpp_lib_freestanding_functional 202306L Yes
__cpp_lib_freestanding_iterator 202306L Yes
__cpp_lib_freestanding_mdspan 202311L Yes
__cpp_lib_freestanding_memory 202502L Yes
__cpp_lib_freestanding_numeric 202502L Yes
__cpp_lib_freestanding_operator_new 202306L Yes
__cpp_lib_freestanding_optional 202311L Yes
__cpp_lib_freestanding_random 202502L Yes
__cpp_lib_freestanding_ranges 202306L Yes
__cpp_lib_freestanding_ratio 202306L Yes
__cpp_lib_freestanding_string_view 202311L <string_view> Yes
__cpp_lib_freestanding_tuple 202306L Yes
__cpp_lib_freestanding_utility 202306L Yes
__cpp_lib_freestanding_variant 202311L Yes
__cpp_lib_fstream_native_handle 202306L
__cpp_lib_function_ref 202306L
__cpp_lib_gcd_lcm 201606L
__cpp_lib_generator 202207L
__cpp_lib_generic_associative_lookup 201304L
__cpp_lib_generic_unordered_lookup 201811L <unordered_map> <unordered_set>
__cpp_lib_hardware_interference_size 201703L Yes
__cpp_lib_has_unique_object_representations 201606L <type_traits> Yes
__cpp_lib_hazard_pointer 202306L <hazard_pointer>
__cpp_lib_hive 202502L
__cpp_lib_hypot 201603L
__cpp_lib_incomplete_container_elements 201505L <forward_list>
__cpp_lib_indirect 202502L
__cpp_lib_inplace_vector 202406L <inplace_vector>
__cpp_lib_int_pow2 202002L Yes
__cpp_lib_integer_comparison_functions 202002L
__cpp_lib_integer_sequence 201304L Yes
__cpp_lib_integral_constant_callable 201304L <type_traits> Yes
__cpp_lib_interpolate 201902L
__cpp_lib_invoke 201411L Yes
__cpp_lib_invoke_r 202106L Yes
__cpp_lib_ios_noreplace 202207L
__cpp_lib_is_aggregate 201703L <type_traits> Yes
__cpp_lib_is_constant_evaluated 201811L <type_traits> Yes
__cpp_lib_is_final 201402L <type_traits> Yes
__cpp_lib_is_implicit_lifetime 202302L <type_traits> Yes
__cpp_lib_is_invocable 201703L <type_traits> Yes
__cpp_lib_is_layout_compatible 201907L <type_traits> Yes
__cpp_lib_is_nothrow_convertible 201806L <type_traits> Yes
__cpp_lib_is_null_pointer 201309L <type_traits> Yes
__cpp_lib_is_pointer_interconvertible 201907L <type_traits> Yes
__cpp_lib_is_scoped_enum 202011L <type_traits> Yes
__cpp_lib_is_sufficiently_aligned 202411L
__cpp_lib_is_swappable 201603L <type_traits> Yes
__cpp_lib_is_virtual_base_of 202406L <type_traits> Yes
__cpp_lib_is_within_lifetime 202306L <type_traits> Yes
__cpp_lib_jthread 201911L <stop_token>
__cpp_lib_latch 201907L
__cpp_lib_launder 201606L Yes
__cpp_lib_linalg 202412L
__cpp_lib_list_remove_return_type 201806L <forward_list>
__cpp_lib_logical_traits 201510L <type_traits> Yes
__cpp_lib_make_from_tuple 201606L Yes
__cpp_lib_make_reverse_iterator 201402L Yes
__cpp_lib_make_unique 201304L
__cpp_lib_map_try_emplace 201411L
__cpp_lib_math_constants 201907L
__cpp_lib_math_special_functions 201603L
__cpp_lib_mdspan 202406L Yes
__cpp_lib_memory_resource 201603L <memory_resource>
__cpp_lib_modules 202207L Yes
__cpp_lib_move_iterator_concept 202207L Yes
__cpp_lib_move_only_function 202110L
__cpp_lib_node_extract 201606L <unordered_map> <unordered_set>
__cpp_lib_nonmember_container_access 201411L <forward_list> <unordered_map> <unordered_set> Yes
__cpp_lib_not_fn 202306L Yes
__cpp_lib_null_iterators 201304L Yes
__cpp_lib_optional 202110L
__cpp_lib_optional_range_support 202406L Yes
__cpp_lib_out_ptr 202311L Yes
__cpp_lib_parallel_algorithm 201603L
__cpp_lib_philox_engine 202406L
__cpp_lib_polymorphic 202502L
__cpp_lib_polymorphic_allocator 201902L <memory_resource>
__cpp_lib_print 202406L
__cpp_lib_quoted_string_io 201304L
__cpp_lib_ranges 202406L
__cpp_lib_ranges_as_const 202311L Yes
__cpp_lib_ranges_as_rvalue 202207L Yes
__cpp_lib_ranges_cache_latest 202411L Yes
__cpp_lib_ranges_cartesian_product 202207L Yes
__cpp_lib_ranges_chunk 202202L Yes
__cpp_lib_ranges_chunk_by 202202L Yes
__cpp_lib_ranges_concat 202403L Yes
__cpp_lib_ranges_contains 202207L
__cpp_lib_ranges_enumerate 202302L
__cpp_lib_ranges_find_last 202207L
__cpp_lib_ranges_fold 202207L
__cpp_lib_ranges_generate_random 202403L
__cpp_lib_ranges_iota 202202L
__cpp_lib_ranges_join_with 202202L Yes
__cpp_lib_ranges_repeat 202207L Yes
__cpp_lib_ranges_reserve_hint 202502L
__cpp_lib_ranges_slide 202202L Yes
__cpp_lib_ranges_starts_ends_with 202106L
__cpp_lib_ranges_stride 202207L Yes
__cpp_lib_ranges_to_container 202202L Yes
__cpp_lib_ranges_to_input 202502L Yes
__cpp_lib_ranges_zip 202110L Yes
__cpp_lib_ratio 202306L Yes
__cpp_lib_raw_memory_algorithms 202411L
__cpp_lib_rcu 202306L
__cpp_lib_reference_from_temporary 202202L <type_traits> Yes
__cpp_lib_reference_wrapper 202403L Yes
__cpp_lib_remove_cvref 201711L <type_traits> Yes
__cpp_lib_result_of_sfinae 201210L <type_traits> Yes
__cpp_lib_robust_nonmodifying_seq_ops 201304L
__cpp_lib_sample 201603L
__cpp_lib_saturation_arithmetic 202311L
__cpp_lib_scoped_lock 201703L
__cpp_lib_semaphore 201907L
__cpp_lib_senders 202406L
__cpp_lib_shared_mutex 201505L <shared_mutex>
__cpp_lib_shared_ptr_arrays 201707L
__cpp_lib_shared_ptr_weak_type 201606L
__cpp_lib_shared_timed_mutex 201402L <shared_mutex>
__cpp_lib_shift 202202L
__cpp_lib_simd 202502L
__cpp_lib_simd_complex 202502L
__cpp_lib_smart_ptr_for_overwrite 202002L
__cpp_lib_smart_ptr_owner_equality 202306L
__cpp_lib_source_location 201907L <source_location> Yes
__cpp_lib_span 202311L Yes
__cpp_lib_span_initializer_list 202311L Yes
__cpp_lib_spanstream 202106L
__cpp_lib_ssize 201902L Yes
__cpp_lib_sstream_from_string_view 202306L
__cpp_lib_stacktrace 202011L
__cpp_lib_start_lifetime_as 202207L Yes
__cpp_lib_starts_ends_with 201711L <string_view>
__cpp_lib_stdatomic_h 202011L <stdatomic.h>
__cpp_lib_string_contains 202011L <string_view>
__cpp_lib_string_resize_and_overwrite 202110L
__cpp_lib_string_udls 201304L
__cpp_lib_string_view 202403L <string_view>
__cpp_lib_submdspan 202411L Yes
__cpp_lib_syncbuf 201803L
__cpp_lib_text_encoding 202306L <text_encoding>
__cpp_lib_three_way_comparison 201907L Yes
__cpp_lib_to_address 201711L Yes
__cpp_lib_to_array 201907L Yes
__cpp_lib_to_chars 202306L
__cpp_lib_to_string 202306L
__cpp_lib_to_underlying 202102L Yes
__cpp_lib_transformation_trait_aliases 201304L <type_traits> Yes
__cpp_lib_transparent_operators 201510L Yes
__cpp_lib_trivially_relocatable 202502L <type_traits> Yes
__cpp_lib_tuple_element_t 201402L Yes
__cpp_lib_tuple_like 202311L <unordered_map>
__cpp_lib_tuples_by_type 201304L Yes
__cpp_lib_type_identity 201806L <type_traits> Yes
__cpp_lib_type_trait_variable_templates 201510L <type_traits> Yes
__cpp_lib_uncaught_exceptions 201411L Yes
__cpp_lib_unordered_map_try_emplace 201411L <unordered_map>
__cpp_lib_unreachable 202202L Yes
__cpp_lib_unwrap_ref 201811L <type_traits> Yes
__cpp_lib_variant 202306L
__cpp_lib_void_t 201411L <type_traits> Yes
Total number of macros: 268

A hardened implementation also defines the following macros:

Macro name Value Header Free-standing
__cpp_lib_hardened_array 202502L
__cpp_lib_hardened_basic_string 202502L
__cpp_lib_hardened_basic_string_view 202502L <string_view>
__cpp_lib_hardened_bitset 202502L
__cpp_lib_hardened_deque 202502L
__cpp_lib_hardened_expected 202502L
__cpp_lib_hardened_forward_list 202502L <forward_list>
__cpp_lib_hardened_inplace_vector 202502L <inplace_vector>
__cpp_lib_hardened_list 202502L
__cpp_lib_hardened_mdspan 202502L
__cpp_lib_hardened_optional 202502L
__cpp_lib_hardened_span 202502L
__cpp_lib_hardened_valarray 202502L
__cpp_lib_hardened_vector 202502L
Total number of macros: 14

[edit] Notes

Each value in "Value" column follows the pattern: "yyyymmL", where "yyyy" is a year, and "mm" is a month when the corresponding feature-set was accepted for standardization. Some values where increased since the time of their introduction, if capabilities of given feature where extended. The table above contains only the most recent values (that is, taken from the latest C++ language draft standard). A full set of values, including the initial and intermediate ones, can be found in this table.

[edit] Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR Applied to Behavior as published Correct behavior
LWG 4126 C++20C++23 some feature-test macros for fullyfreestanding features were not freestanding they are alsofreestanding

[edit] See also

Feature testing (C++20) A set of preprocessor macros to test the corresponding to C++ language and library features
C++ documentation for Headers required for a freestanding implementation
C++ documentation for Predefined Macro Symbols