The Linux Manuals (man pages) document is an important part of Linux documents. Linux Manuals are organized as several sections. Each section has a group of commands for a specific area in Linux usage, administration or development.
std::identity – std::identity Synopsis Defined in header <functional> struct identity; (since C++20) std::identity is a function object type whose operator() returns its argument unchanged. Member types Member type Definition is_transparent /* unspecified */ Member functions returns the argument unchanged operator() (public member function) std::identity::operator() template< class T> constexpr T&& operator()( T&& t ) const noexcept;…
std::hypot,std::hypotf,std::hypotl – std::hypot,std::hypotf,std::hypotl Synopsis Defined in header <cmath> float hypot ( float x, float y ); (1) (since C++11) float hypotf( float x, float y ); double hypot ( double x, double y ); (2) (since C++11) long double hypot ( long double x, long double y ); (3) (since C++11) long double hypotl( long…
std::holds_alternative – std::holds_alternative Synopsis Defined in header<variant> template <class T, class… Types> (since C++ 17) constexpr bool holds_alternative(const std::variant<Types…> &v) noexcept; Checks if the variant v holds the alternative T. The call is ill-formed if T does not appear exactly once in Types… Parameters v – variant to examine Return value true if the variant…
std::hermite,std::hermitef,std::hermitel – std::hermite,std::hermitef,std::hermitel Synopsis double hermite(unsigned int n, double x); float hermite(unsigned int n, float x); long double hermite(unsigned int n, long double x); (1)(since C++ 17) float hermitef(unsigned int n, float x); long double hermitel(unsigned int n, long double x); double hermite(unsigned int n, IntegralType x); (2)(since C++ 17) 1) Computes the (physicist’s) Hermite_polynomials…
std::hash<std::variant> – std::hash<std::variant> Synopsis Defined in header<variant> template <class… Types> (since C++ 17) struct hash<std::variant<Types…>>; The template specialization of std::hash for the std::variant template allows users to obtain hashes of variant objects. The specialization std::hash<std::variant<Types…>> is enabled (see std::hash) if every specialization in std::hash<std::remove_const_t<Types>>… is enabled, and is disabled otherwise. The member functions of this…
std::hash(std::vector<bool>) – std::hash(std::vector<bool>) Synopsis template <class Allocator> struct hash<vector<bool, Allocator>>; (since C++11) The template specialization of std::hash for std::vector<bool> allows users to obtain hashes of objects of type std::vector<bool>. Example This section is incomplete Reason: no example See also hash hash function object (class template) (C++11)
std::hash(std::string_view,std::wstring_view,std::u16string_view,std::u32string_view) – std::hash(std::string_view,std::wstring_view,std::u16string_view,std::u32string_view) Synopsis Defined in header <string_view> template<> struct hash<std::string_view>; (since C++17) template<> struct hash<std::wstring_view>; (since C++17) template<> struct hash<std::u8string_view>; (since C++20) template<> struct hash<std::u16string_view>; (since C++17) template<> struct hash<std::u32string_view>; (since C++17) Template specializations of std::hash for the various view classes for hashing views. These hashes equal the hashes of corresponding std::basic_string classes: If…
std::hash(std::string,std::wstring,std::u16string,std::u32string,std::pmr::string,std::pmr::wstring,std::pmr::u16string,std::pmr::u32string) – std::hash(std::string,std::wstring,std::u16string,std::u32string,std::pmr::string,std::pmr::wstring,std::pmr::u16string,std::pmr::u32string) Synopsis Defined in header<string> template <> struct hash<std::string>; template <> struct hash<std::wstring>; template <> struct hash<std::u8string>; // c++20 (since C++11) template <> struct hash<std::u16string>; template <> struct hash<std::u32string>; template <> struct hash<std::pmr::string>; template <> struct hash<std::pmr::wstring>; template <> struct hash<std::pmr::u8string>; (since C++ 20) template <> struct hash<std::pmr::u16string>; template <> struct hash<std::pmr::u32string>; The…
std::hash(std::string,std::wstring,std::u16string,std::u32string,std::pmr::string, – std::hash(std::string,std::wstring,std::u16string,std::u32string,std::pmr::string, Synopsis Defined in header<string> template <> struct hash<std::string>; template <> struct hash<std::wstring>; template <> struct hash<std::u8string>; // c++20 (since C++11) template <> struct hash<std::u16string>; template <> struct hash<std::u32string>; template <> struct hash<std::pmr::string>; template <> struct hash<std::pmr::wstring>; template <> struct hash<std::pmr::u8string>; (since C++ 20) template <> struct hash<std::pmr::u16string>; template <> struct hash<std::pmr::u32string>; The…
std::hash(std::shared_ptr) – std::hash(std::shared_ptr) Synopsis template<class T> struct hash<shared_ptr<T>>; (since C++11) The template specialization of std::hash for std::shared_ptr<T> allows users to obtain hashes of objects of type std::shared_ptr<T>. For a given std::shared_ptr<T> p, this specialization ensures that std::hash<std::shared_ptr<T>>()(p) == std::hash<T*>()(p.get()). (until C++17) std::hash<std::shared_ptr<T>>()(p) == std::hash<typename std::shared_ptr<T>::element_type*>()(p.get()). (since C++17) Example This section is incomplete Reason: no example…
std::hash(std::experimental::string_view,std::experimental::wstring_view,std::experimental::u16string_view,std::experimental::u32string_view) – std::hash(std::experimental::string_view,std::experimental::wstring_view,std::experimental::u16string_view,std::experimental::u32string_view) Synopsis Defined in header<experimental / string_view> template <> struct hash<std::experimental::string_view>; template <> struct hash<std::experimental::wstring_view>; (library fundamentals TS) template <> struct hash<std::experimental::u16string_view>; template <> struct hash<std::experimental::u32string_view>; Template specializations of std::hash for the various view classes for hashing views. See also hash hash function object (class template) (C++11)
std::hash(std::experimental::string_view,std::experimental::wstring_view, – std::hash(std::experimental::string_view,std::experimental::wstring_view, Synopsis Defined in header<experimental / string_view> template <> struct hash<std::experimental::string_view>; template<> struct hash<std::experimental::wstring_view>; (library fundamentals template<> struct hash<std::experimental::u16string_view>; TS) template <> struct hash<std::experimental::u32string_view>; Template specializations of std::hash for the various view classes for hashing views. See also hash hash function object (C++11) (class template)
std::hash(std::experimental::shared_ptr) – std::hash(std::experimental::shared_ptr) Synopsis template<class T> struct hash<std::experimental::shared_ptr<T>>; (library fundamentals TS) The template specialization of std::hash for std::experimental::shared_ptr<T> allows users to obtain hashes of objects of type std::experimental::shared_ptr<T>. For a given std::experimental::shared_ptr<T> p, this specialization ensures that std::hash<std::experimental::shared_ptr<T>>()(p) == std::hash<T*>()(p.get()). Example This section is incomplete Reason: no example See also hash hash function object (class…
std::hash(std::experimental::propagate_const) – std::hash(std::experimental::propagate_const) Synopsis Defined in header <experimental/propagate_const> template<class T> struct hash<std::experimental::propagate_const<T>>; (library fundamentals TS v2) The template specialization of std::hash for std::experimental::propagate_const<T> allows users to obtain hashes of objects of type std::experimental::propagate_const<T>. For a given std::experimental::propagate_const<T> p, this specialization ensures that std::hash<std::experimental::propagate_const<T>>()(p) == std::hash<T>()(p.t_), where p.t_ is the pointer-like object wrapped by p. Example…
std::hash(std::experimental::observer_ptr) – std::hash(std::experimental::observer_ptr) Synopsis Defined in header <experimental/memory> template<class T> struct hash<std::experimental::observer_ptr<T>>; (library fundamentals TS v2) The template specialization of std::hash for std::experimental::observer_ptr<T> allows users to obtain hashes of objects of type std::experimental::observer_ptr<T>. For a given std::experimental::observer_ptr<T> p, this specialization ensures that std::hash<std::experimental::observer_ptr<T>>()(p) == std::hash<T*>()(p.get()). Example This section is incomplete Reason: no example See also…
std::hash(std::bitset) – std::hash(std::bitset) Synopsis template<size_t N> struct hash<bitset<N>>; (since C++11) The template specialization of std::hash for std::bitset<N> allows users to obtain hashes of objects of type std::bitset<N>. Example The following code shows one possible output of a hash function used on several bitsets: // Run this code #include <iostream> #include <bitset> #include <functional> int main()…
std::has_virtual_destructor – std::has_virtual_destructor Synopsis Defined in header<type_traits> template <class T> (since C++ 11) struct has_virtual_destructor; If T is a type with a virtual destructor, provides the member constant value equal true. For any other type, value is false. If T is a non-union class type, T shall be a complete type; otherwise, the behavior is…
std::has_unique_object_representations – std::has_unique_object_representations Synopsis Defined in header<type_traits> template <class T> (since C++ 17) struct has_unique_object_representations; If T is TriviallyCopyable and if any two objects of type T with the same value have the same object_representation, provides the member constant value equal true. For any other type, value is false. For the purpose of this trait,…
std::has_trivial_default_constructor< _Tp > – Synopsis Inherits std::integral_constant< bool, __has_trivial_constructor(_Tp)>. Public Types typedef integral_constant < bool, __v > type" typedef bool value_type Public Member Functions constexpr operator value_type () Static Public Attributes static constexpr bool value Detailed Description template<typename _Tp>struct std::has_trivial_default_constructor< _Tp > has_trivial_default_constructor (temporary legacy) Definition at line 1211 of file type_traits. Author Generated automatically…
std::has_trivial_copy_constructor< _Tp > – Synopsis Inherits std::integral_constant< bool, __has_trivial_copy(_Tp)>. Public Types typedef integral_constant < bool, __v > type" typedef bool value_type Public Member Functions constexpr operator value_type () Static Public Attributes static constexpr bool value Detailed Description template<typename _Tp>struct std::has_trivial_copy_constructor< _Tp > has_trivial_copy_constructor (temporary legacy) Definition at line 1217 of file type_traits. Author Generated automatically…