Section 3: library functions
std::greater<void> – std::greater<void> Synopsis Defined in header<functional> template <> (since C++ 14) class greater<void>; std::greater<> is a specialization of std::greater with parameter and return type deduced. Member types Member type Definition is_transparent /* unspecified */ Member functions tests if the lhs compares greater than rhs operator() (public member function) std::greater<>::operator() template< class T, class U>…
std::gmtime – std::gmtime Synopsis Defined in header<ctime> std::tm *gmtime(const std::time_t *time); Converts given time since epoch as std::time_t value into calendar time, expressed in Coordinated Universal Time (UTC). Parameters time – pointer to a time_t object to convert Return value Pointer to a static internal std::tm object on success, or null pointer otherwise. The structure…
std::getwchar – std::getwchar Synopsis Defined in header <cwchar> wint_t getwchar(); Reads the next wide character from stdin. Parameters (none) Return value The obtained wide character or WEOF if an error has occurred or the end of file reached See also reads a character from stdin getchar (function) gets a wide character from a file stream…
std::gets – std::gets Synopsis Defined in header <cstdio> char* gets( char* str ); (deprecated in C++11) (removed in C++14) Reads stdin into given character string until a newline character is found or end-of-file occurs. Parameters str – character string to be written Return value str on success, NULL on failure. If the failure has been…
std::getline – std::getline Synopsis Defined in header <string> template< class CharT, class Traits, class Allocator > std::basic_istream<CharT,Traits>& getline( std::basic_istream<CharT,Traits>& input, (1) std::basic_string<CharT,Traits,Allocator>& str, CharT delim ); template< class CharT, class Traits, class Allocator > std::basic_istream<CharT,Traits>& getline( std::basic_istream<CharT,Traits>&& input, (1) (since C++11) std::basic_string<CharT,Traits,Allocator>& str, CharT delim ); template< class CharT, class Traits, class Allocator > std::basic_istream<CharT,Traits>&…
std::getenv – std::getenv Synopsis Defined in header<cstdlib> char *getenv(const char *env_var); Searches the environment list provided by the host environment (the OS), for a string that matches the C string pointed to by env_var and returns a pointer to the C string that is associated with the matched environment list member. This function is not…
std::getchar – std::getchar Synopsis Defined in header<cstdio> int getchar(); Reads the next character from stdin. Equivalent to std::getc(stdin). Parameters (none) Return value The obtained character on success or EOF on failure. If the failure has been caused by end of file condition, additionally sets the eof indicator (see feof()) on stdin. If the failure has…
std::get_unexpected – std::get_unexpected Synopsis Defined in header <exception> (since C++11) std::unexpected_handler get_unexpected() noexcept; (deprecated) (removed in C++17) Returns the currently installed std::unexpected_handler, which may be a null pointer. This function is thread-safe. Prior call to std::set_unexpected synchronizes-with (see std::memory_order) the subsequent calls to this function. Parameters (none) Return value The currently installed std::unexpected_handler. See also…
std::get_time – std::get_time Synopsis Defined in header<iomanip> template <class CharT> (since C++ 11) /*unspecified*/ get_time(std::tm *tmb, const CharT *fmt); When used in an expression in >> get_time(tmb, fmt), parses the character input as a date/time value according to format string fmt according to the std::time_get facet of the locale currently imbued in the input stream…
std::get_terminate – std::get_terminate Synopsis Defined in header <exception> std::terminate_handler get_terminate() noexcept; (since C++11) Returns the currently installed std::terminate_handler, which may be a null pointer. This function is thread-safe. Prior call to std::set_terminate synchronizes-with (see std::memory_order) this function. (since C++11) Parameters (none) Return value The currently installed std::terminate_handler. See also the type of the function called…
std::get_temporary_buffer – std::get_temporary_buffer Synopsis Defined in header <memory> template< class T > (deprecated in C++17) std::pair< T*, std::ptrdiff_t > get_temporary_buffer( std::ptrdiff_t count ); (removed in C++20) Allocates uninitialized contiguous storage, which should be sufficient to store up to count adjacent objects of type T. The request is non-binding and the implementation may allocate less or…
std::get_pointer_safety – std::get_pointer_safety Synopsis Defined in header <memory> std::pointer_safety get_pointer_safety() noexcept; (since C++11) Obtains the implementation-defined pointer safety model, which is a value of type std::pointer_safety. Parameters (none) Return value The pointer safety used by this implementation. Example // Run this code #include <iostream> #include <memory> int main() { std::cout << "Pointer safety: "; switch…
std::get_new_handler – std::get_new_handler Synopsis Defined in header <new> std::new_handler get_new_handler() noexcept; (since C++11) Returns the currently installed new-handler, which may be a null pointer. This function is thread-safe. Previous call to std::set_new_handler synchronizes-with (see std::memory_order) the subsequent calls to std::get_new_handler. (since C++11) Parameters (none) Return value The currently installed new-handler, which may be a null…
std::get_money – std::get_money Synopsis Defined in header <iomanip> template< class MoneyT > (since C++11) /*unspecified*/ get_money( MoneyT& mon, bool intl = false ); When used in an expression in >> get_money(mon, intl), parses the character input as a monetary value, as specified by the std::money_get facet of the locale currently imbued in in, and stores…
std::get_if – std::get_if Synopsis Defined in header<variant> template <std::size_t I, class… Types> constexpr std::add_pointer_t< std::variant_alternative_t<I, std::variant<Types…>> > get_if(std::variant<Types…> *pv) noexcept; template <std::size_t I, class… Types> constexpr std::add_pointer_t<(1)(since C++ 17) const std::variant_alternative_t<I, variant<Types…>> > get_if(const std::variant<Types…> *pv) noexcept; template <class T, class… Types> constexpr std::add_pointer_t<T> get_if(std::variant<Types…> *pv) noexcept; (2)(since C++ 17) template <class T, class… Types>…
std::get_deleter – std::get_deleter Synopsis template <class Deleter, class T> (since C++ 11) Deleter *get_deleter(const std::shared_ptr<T> &p) noexcept; Access to the p’s deleter. If the shared pointer p owns a deleter of type cv-unqualified Deleter (e.g. if it was created with one of the constructors that take a deleter as a parameter), then returns a pointer…
std::get(std::variant) – std::get(std::variant) Synopsis Defined in header<variant> template <std::size_t I, class… Types> constexpr std::variant_alternative_t< I, std::variant<Types…> > & get(std::variant<Types…> &v); template <std::size_t I, class… Types> constexpr std::variant_alternative_t< I, std::variant<Types…> > && get(std::variant<Types…> &&v); template <std::size_t I, class… Types> constexpr std::variant_alternative_t< I, std::variant<Types…> > const & get(const std::variant<Types…> &v); (1)(since C++ 17) template <std::size_t I, class……
std::get(std::tuple) – std::get(std::tuple) Synopsis template <std::size_t I, class… Types> (since C++ 11) typename std::tuple_element<I, tuple<Types…>>::type &(1)(constexpr since C++ 14) get(tuple<Types…> &t) noexcept; template <std::size_t I, class… Types> (since C++ 11) typename std::tuple_element<I, tuple<Types…>>::type && (2)(constexpr since C++ 14) get(tuple<Types…> &&t) noexcept; template <std::size_t I, class… Types> (since C++ 11) typename std::tuple_element<I, tuple<Types…>>::type const &(3)(constexpr since…
std::get(std::span) – std::get(std::span) Synopsis template< std::size_t I, class T, std::size_t N > (since C++20) constexpr T& get( std::span<T,N> s ) noexcept; Obtains a reference to the Ith element of the span s. The span must have static extent (i.e., N != std::dynamic_extent) and I must be an integer value in range [0, N). This is…
std::get(std::pair) – std::get(std::pair) Synopsis Defined in header<utility> template <size_t I, class T1, class T2> (since C++ 11) typename std::tuple_element<I, std::pair<T1, T2>>::type &(1)(until C++ 14) get(pair<T1, T2> &p) noexcept; template <size_t I, class T1, class T2> constexpr std::tuple_element_t<I, std::pair<T1, T2>> &(1)(since C++ 14) get(pair<T1, T2> &p) noexcept; template <size_t I, class T1, class T2> (since C++…