C++ standard libraries extensions

C++ standard libraries extensions - cppreference.com

Version 1 of the C++ Extensions for Library Fundamentals, ISO/IEC TS 19568:2015 defines the following new components for the C++ standard library:

Not selected for inclusion in C++17

The following components of ISO/IEC TS 19568:2015 were not selected for inclusion in C++17.

Modified versions of existing classes to support type-erased allocators


	a modified version of std::function with support for type-erased allocators (class template)

	a modified version of std::promise with support for type-erased allocators (class template)
	a modified version of std::packaged_task with support for type-erased allocators (class template)

Memory resource adaptors

General utilities

Feature test macros

Defined in header `<experimental/optional>`
__cpp_lib_experimental_optional	a value of at least `201411` indicates that the optional type is supported (macro constant)
Defined in header `<experimental/any>`
__cpp_lib_experimental_any	a value of at least `201411` indicates that the any type is supported (macro constant)
Defined in header `<experimental/string_view>`
__cpp_lib_experimental_string_view	a value of at least `201411` indicates that basic_string_view template is supported (macro constant)
Defined in header `<experimental/tuple>`
__cpp_lib_experimental_apply	a value of at least `201402` indicates that the tuple apply() function is supported (macro constant)
Defined in header `<experimental/type_traits>`
__cpp_lib_experimental_type_trait_variable_templates	a value of at least `201402` indicates that variable template type traits are supported (macro constant)
__cpp_lib_experimental_invocation_type	a value of at least `201406` indicates that invocation type traits are supported (macro constant)
Defined in header `<experimental/functional>`
__cpp_lib_experimental_boyer_moore_searching	a value of at least `201411` indicates that additional searching algorithms are supported (macro constant)
__cpp_lib_experimental_function_erased_allocator	a value of at least `201406` indicates that type-erased allocator for std::function is supported (macro constant)
Defined in header `<experimental/future>`
__cpp_lib_experimental_promise_erased_allocator	a value of at least `201406` indicates that type-erased allocator for std::promise is supported (macro constant)
__cpp_lib_experimental_packaged_task_erased_allocator	a value of at least `201406` indicates that type-erased allocator for std::packaged_task is supported (macro constant)
Defined in header `<experimental/memory>`
__cpp_lib_experimental_shared_ptr_arrays	a value of at least `201406` indicates that shared_ptr arrays are supported (macro constant)
Defined in header `<experimental/memory_resource>`
__cpp_lib_experimental_memory_resources	a value of at least `201402` indicates that polymorphic memory resources are supported (macro constant)
Defined in header `<experimental/algorithm>`
__cpp_lib_experimental_sample	a value of `201402` indicates that the sample algorithm is supported (macro constant)

Merged into C++17

The following components of ISO/IEC TS 19568:2015 were included into C++17.

optional objects

class `any`

`string_view`

Type-erased and polymorphic allocators

Polymorphic allocators and memory resources

The entities in this section are declared in the std::experimental::pmr namespace.

Defined in header `<experimental/memory_resource>`
memory_resource	an abstract interface for classes that encapsulate memory resources (class)
synchronized_pool_resource	a thread-safe std::experimental::pmr::memory_resource for managing allocations in pools of different block sizes (class) [edit]
unsynchronized_pool_resource	a thread-unsafe std::experimental::pmr::memory_resource for managing allocations in pools of different block sizes (class) [edit]
monotonic_buffer_resource	a special-purpose memory_resource that releases the allocated memory only when the resource is destroyed (class)
polymorphic_allocator	an allocator that supports run-time polymorphism based on the memory_resource it is constructed with (class template)
new_delete_resource	returns a static program-wide `memory_resource` that uses the global operator new and operator delete to allocate and deallocate memory (function) [edit]
null_memory_resource	returns a static `memory_resource` that performs no allocation (function) [edit]
get_default_resource	gets the default `memory_resource` (function) [edit]
set_default_resource	sets the default `memory_resource` (function) [edit]

Convenience aliases for containers using polymorphic allocators

Convenience aliases and alias templates for containers using polymorphic allocators are provided in the std::experimental::pmr namespace for the following class templates in the standard library:

List of container templates for which convenience aliases are provided
std::vector std::deque std::forward_list std::list std::basic_string std::map std::multimap std::set std::multiset std::match_results std::unordered_map std::unordered_multimap std::unordered_set std::unordered_multiset

Array support for `shared_ptr`


Class	Description
	a modified version of std::shared_ptr that supports arrays (class template)
	a modified version of std::weak_ptr that supports arrays (class template)

Sampling and searching algorithms

Defined in header `<experimental/algorithm>`
sample	selects n random elements from a sequence (function template)
search	applies a Searcher to a sequence (function template)
Defined in header `<experimental/functional>`
default_searcher	standard C++ library search algorithm implementation (class template)
make_default_searcher	helper function to create a default_searcher (function template)
boyer_moore_searcher	Boyer-Moore search algorithm implementation (class template)
make_boyer_moore_searcher	helper function to create a boyer_moore_searcher (function template)
boyer_moore_horspool_searcher	Boyer-Moore-Horspool search algorithm implementation (class template)
make_boyer_moore_horspool_searcher	helper function to create a boyer_moore_horspool_searcher (function template)

General utilities

In addition, the TS provides numerous constexpr variable templates for the following type traits and other class templates in the standard library:

List of type traits and other class templates for which variable templates are provided
std::is_void std::is_null_pointer std::is_integral std::is_floating_point std::is_array std::is_pointer std::is_lvalue_reference std::is_rvalue_reference std::is_member_object_pointer std::is_member_function_pointer std::is_enum std::is_union std::is_class std::is_function std::is_reference std::is_arithmetic std::is_fundamental std::is_object std::is_scalar std::is_compound std::is_member_pointer std::is_const std::is_volatile std::is_trivial std::is_trivially_copyable std::is_standard_layout std::is_pod std::is_literal_type std::is_empty std::is_polymorphic std::is_abstract std::is_final std::is_signed std::is_unsigned std::is_constructible std::is_trivially_constructible std::is_nothrow_constructible std::is_default_constructible std::is_trivially_default_constructible std::is_nothrow_default_constructible std::is_copy_constructible std::is_trivially_copy_constructible std::is_nothrow_copy_constructible std::is_move_constructible std::is_trivially_move_constructible std::is_nothrow_move_constructible std::is_assignable std::is_trivially_assignable std::is_nothrow_assignable std::is_copy_assignable std::is_trivially_copy_assignable std::is_nothrow_copy_assignable std::is_move_assignable std::is_trivially_move_assignable std::is_nothrow_move_assignable std::is_destructible std::is_trivially_destructible std::is_nothrow_destructible std::has_virtual_destructor std::alignment_of std::rank std::extent std::is_same std::is_base_of std::is_convertible std::ratio_equal std::ratio_not_equal std::ratio_less std::ratio_less_equal std::ratio_greater std::ratio_greater_equal std::tuple_size std::chrono::treat_as_floating_point std::is_error_code_enum std::is_error_condition_enum std::is_bind_expression std::is_placeholder std::uses_allocator

List of type traits and other class templates for which variable templates are provided

std::is_void
std::is_null_pointer
std::is_integral
std::is_floating_point
std::is_array
std::is_pointer
std::is_lvalue_reference
std::is_rvalue_reference
std::is_member_object_pointer
std::is_member_function_pointer
std::is_enum
std::is_union
std::is_class
std::is_function
std::is_reference
std::is_arithmetic
std::is_fundamental
std::is_object
std::is_scalar
std::is_compound
std::is_member_pointer
std::is_const
std::is_volatile
std::is_trivial
std::is_trivially_copyable
std::is_standard_layout
std::is_pod
std::is_literal_type
std::is_empty
std::is_polymorphic
std::is_abstract
std::is_final
std::is_signed
std::is_unsigned
std::is_constructible
std::is_trivially_constructible
std::is_nothrow_constructible
std::is_default_constructible
std::is_trivially_default_constructible
std::is_nothrow_default_constructible
std::is_copy_constructible
std::is_trivially_copy_constructible
std::is_nothrow_copy_constructible
std::is_move_constructible
std::is_trivially_move_constructible
std::is_nothrow_move_constructible
std::is_assignable
std::is_trivially_assignable
std::is_nothrow_assignable
std::is_copy_assignable
std::is_trivially_copy_assignable
std::is_nothrow_copy_assignable
std::is_move_assignable
std::is_trivially_move_assignable
std::is_nothrow_move_assignable
std::is_destructible
std::is_trivially_destructible
std::is_nothrow_destructible
std::has_virtual_destructor
std::alignment_of
std::rank
std::extent
std::is_same
std::is_base_of
std::is_convertible
std::ratio_equal
std::ratio_not_equal
std::ratio_less
std::ratio_less_equal
std::ratio_greater
std::ratio_greater_equal
std::tuple_size
std::chrono::treat_as_floating_point
std::is_error_code_enum
std::is_error_condition_enum
std::is_bind_expression
std::is_placeholder
std::uses_allocator

Not selected for inclusion in C++17

Modified versions of existing classes to support type-erased allocators

Memory resource adaptors

General utilities

Feature test macros

Merged into C++17

optional objects

class any

string_view

Type-erased and polymorphic allocators

Polymorphic allocators and memory resources

Convenience aliases for containers using polymorphic allocators

Array support for shared_ptr

Sampling and searching algorithms

General utilities

class `any`

`string_view`

Array support for `shared_ptr`