CMAKE_CXX_KNOWN_FEATURES

Added in version 3.1.

List of C++ features known to this version of CMake.

The features listed in this global property may be known to be available to the C++ compiler. If the feature is available with the C++ compiler, it will be listed in the CMAKE_CXX_COMPILE_FEATURES variable.

The features listed here may be used with the target_compile_features() command. See the cmake-compile-features(7) manual for information on compile features and a list of supported compilers.

The features known to this version of CMake are listed below.

High level meta features indicating C++ standard support

Added in version 3.8.

The following meta features indicate general support for the associated language standard. It reflects the language support claimed by the compiler, but it does not necessarily imply complete conformance to that standard.

cxx_std_98

Compiler mode is at least C++ 98.

cxx_std_11

Compiler mode is at least C++ 11.

cxx_std_14

Compiler mode is at least C++ 14.

cxx_std_17

Compiler mode is at least C++ 17.

cxx_std_20

Added in version 3.12.

Compiler mode is at least C++ 20.

cxx_std_23

Added in version 3.20.

Compiler mode is at least C++ 23.

cxx_std_26

Added in version 3.30.

Compiler mode is at least C++ 26.

Note

If the compiler's default standard level is at least that of the requested feature, CMake may omit the -std= flag. The flag may still be added if the compiler's default extensions mode does not match the <LANG>_EXTENSIONS target property, or if the <LANG>_STANDARD target property is set.

Low level individual compile features

For C++ 11 and C++ 14, compilers were sometimes slow to implement certain language features. CMake provided some individual compile features to help projects determine whether specific features were available. These individual features are now less relevant and projects should generally prefer to use the high level meta features instead. Individual compile features are not provided for C++ 17 or later.

See the cmake-compile-features(7) manual for further discussion of the use of individual compile features.

Individual features from C++ 98

cxx_template_template_parameters

Template template parameters, as defined in ISO/IEC 14882:1998.

Individual features from C++ 11

cxx_alias_templates

Template aliases, as defined in N2258.

cxx_alignas

Alignment control alignas, as defined in N2341.

cxx_alignof

Alignment control alignof, as defined in N2341.

cxx_attributes

Generic attributes, as defined in N2761.

cxx_auto_type

Automatic type deduction, as defined in N1984.

cxx_constexpr

Constant expressions, as defined in N2235.

cxx_decltype_incomplete_return_types

Decltype on incomplete return types, as defined in N3276.

cxx_decltype

Decltype, as defined in N2343.

cxx_default_function_template_args

Default template arguments for function templates, as defined in DR226

cxx_defaulted_functions

Defaulted functions, as defined in N2346.

cxx_defaulted_move_initializers

Defaulted move initializers, as defined in N3053.

cxx_delegating_constructors

Delegating constructors, as defined in N1986.

cxx_deleted_functions

Deleted functions, as defined in N2346.

cxx_enum_forward_declarations

Enum forward declarations, as defined in N2764.

cxx_explicit_conversions

Explicit conversion operators, as defined in N2437.

cxx_extended_friend_declarations

Extended friend declarations, as defined in N1791.

cxx_extern_templates

Extern templates, as defined in N1987.

cxx_final

Override control final keyword, as defined in N2928, N3206 and N3272.

cxx_func_identifier

Predefined __func__ identifier, as defined in N2340.

cxx_generalized_initializers

Initializer lists, as defined in N2672.

cxx_inheriting_constructors

Inheriting constructors, as defined in N2540.

cxx_inline_namespaces

Inline namespaces, as defined in N2535.

cxx_lambdas

Lambda functions, as defined in N2927.

cxx_local_type_template_args

Local and unnamed types as template arguments, as defined in N2657.

cxx_long_long_type

long long type, as defined in N1811.

cxx_noexcept

Exception specifications, as defined in N3050.

cxx_nonstatic_member_init

Non-static data member initialization, as defined in N2756.

cxx_nullptr

Null pointer, as defined in N2431.

cxx_override

Override control override keyword, as defined in N2928, N3206 and N3272.

cxx_range_for

Range-based for, as defined in N2930.

cxx_raw_string_literals

Raw string literals, as defined in N2442.

cxx_reference_qualified_functions

Reference qualified functions, as defined in N2439.

cxx_right_angle_brackets

Right angle bracket parsing, as defined in N1757.

cxx_rvalue_references

R-value references, as defined in N2118.

cxx_sizeof_member

Size of non-static data members, as defined in N2253.

cxx_static_assert

Static assert, as defined in N1720.

cxx_strong_enums

Strongly typed enums, as defined in N2347.

cxx_thread_local

Thread-local variables, as defined in N2659.

cxx_trailing_return_types

Automatic function return type, as defined in N2541.

cxx_unicode_literals

Unicode string literals, as defined in N2442.

cxx_uniform_initialization

Uniform initialization, as defined in N2640.

cxx_unrestricted_unions

Unrestricted unions, as defined in N2544.

cxx_user_literals

User-defined literals, as defined in N2765.

cxx_variadic_macros

Variadic macros, as defined in N1653.

cxx_variadic_templates

Variadic templates, as defined in N2242.

Individual features from C++ 14

cxx_aggregate_default_initializers

Aggregate default initializers, as defined in N3605.

cxx_attribute_deprecated

[[deprecated]] attribute, as defined in N3760.

cxx_binary_literals

Binary literals, as defined in N3472.

cxx_contextual_conversions

Contextual conversions, as defined in N3323.

cxx_decltype_auto

decltype(auto) semantics, as defined in N3638.

cxx_digit_separators

Digit separators, as defined in N3781.

cxx_generic_lambdas

Generic lambdas, as defined in N3649.

cxx_lambda_init_captures

Initialized lambda captures, as defined in N3648.

cxx_relaxed_constexpr

Relaxed constexpr, as defined in N3652.

cxx_return_type_deduction

Return type deduction on normal functions, as defined in N3386.

cxx_variable_templates

Variable templates, as defined in N3651.