Section 3: library functions
std::destroy_at – std::destroy_at Synopsis Defined in header<memory> template <class T> (since C++ 17) void destroy_at(T *p); Calls the destructor of the object pointed to by p, as if by p->~T(). Parameters p – a pointer to the object to be destroyed Return value (none) Possible implementation template<class T> void destroy_at(T* p) { p->~T(); } Example…
std::destroy – std::destroy Synopsis Defined in header<memory> template <class ForwardIt> (1)(since C++ 17) void destroy(ForwardIt first, ForwardIt last); template <class ExecutionPolicy, class ForwardIt> (2)(since C++ 17) void destroy(ExecutionPolicy &&policy, ForwardIt first, ForwardIt last); 1) Destroys the objects in the range [first, last), as if by for (; first != last; ++first) std::destroy_at(std::addressof(*first)); 2) Same as…
std::deque<T,Allocator>::~deque – std::deque<T,Allocator>::~deque Synopsis ~deque(); Destructs the container. The destructors of the elements are called and the used storage is deallocated. Note, that if the elements are pointers, the pointed-to objects are not destroyed. Complexity Linear in the size of the container.
std::defer_lock_t,std::try_to_lock_t,std::adopt_lock_t – std::defer_lock_t,std::try_to_lock_t,std::adopt_lock_t Synopsis Defined in header<mutex> struct defer_lock_t { }; (since C++ 11) struct try_to_lock_t { }; (until C++ 17) struct adopt_lock_t { }; struct defer_lock_t { explicit defer_lock_t() = default; }; struct try_to_lock_t { explicit try_to_lock_t() = default; }; (since C++ 17) struct adopt_lock_t { explicit adopt_lock_t() = default; }; std::defer_lock_t, std::try_to_lock_t and…
std::defer_lock,std::try_to_lock,std::adopt_lock – std::defer_lock,std::try_to_lock,std::adopt_lock Synopsis Defined in header <mutex> constexpr std::defer_lock_t defer_lock {}; (since C++11) (until C++17) inline constexpr std::defer_lock_t defer_lock {}; (since C++17) constexpr std::try_to_lock_t try_to_lock {}; (since C++11) (until C++17) inline constexpr std::try_to_lock_t try_to_lock {}; (since C++17) constexpr std::adopt_lock_t adopt_lock {}; (since C++11) (until C++17) inline constexpr std::adopt_lock_t adopt_lock {}; (since C++17) std::defer_lock, std::try_to_lock…
std::default_searcher – std::default_searcher Synopsis Defined in header <functional> template< class ForwardIt, class BinaryPredicate = std::equal_to<> > (since C++17) class default_searcher; A class suitable for use with Searcher overload of std::search that delegates the search operation to the pre-C++17 standard library’s std::search. default_searcher is CopyConstructible and CopyAssignable. Member functions std::default_searcher::default_searcher default_searcher( ForwardIt pat_first, (since C++17) ForwardIt…
std::default_delete – std::default_delete Synopsis Defined in header <memory> template< class T > struct default_delete; (1) (since C++11) template< class T > struct default_delete<T[]>; (2) (since C++11) std::default_delete is the default destruction policy used by std::unique_ptr when no deleter is specified. 1) The non-specialized default_delete uses delete to deallocate memory for a single object. 2) A…
std::declval – std::declval Synopsis Defined in header<utility> template <class T> (since C++ 11) typename std::add_rvalue_reference<T>::type declval() noexcept; Converts any type T to a reference type, making it possible to use member functions in decltype expressions without the need to go through constructors. declval is commonly used in templates where acceptable template parameters may have no…
std::declare_reachable – std::declare_reachable Synopsis Defined in header <memory> void declare_reachable( void* p ); (since C++11) Declares the object referenced by the pointer p reachable. Reachable objects will not be deleted by the garbage collector or considered to be a leak by a leak detector even if all pointers to it are destroyed. An object may…
std::declare_no_pointers – std::declare_no_pointers Synopsis Defined in header <memory> void declare_no_pointers( char *p, std::size_t n ); (since C++11) Informs the garbage collector or leak detector that the specified memory region (n bytes beginning at the byte pointed to by p) contains no traceable pointers. If any part of the region is within an allocated object, the…
std::decimal::decimal64 – Synopsis Public Types typedef float __decfloat64 __attribute__ ((mode(DD))) Public Member Functions decimal64 (decimal32 d32) decimal64 (decimal128 d128) decimal64 (float __r) decimal64 (double __r) decimal64 (long double __r) decimal64 (int __z) decimal64 (unsigned int __z) decimal64 (long __z) decimal64 (unsigned long __z) decimal64 (long long __z) decimal64 (unsigned long long __z) decimal64 (__decfloat64 __z)…
std::decimal::decimal32 – Synopsis Public Types typedef float __decfloat32 __attribute__ ((mode(SD))) Public Member Functions decimal32 (decimal64 __d64) decimal32 (decimal128 __d128) decimal32 (float __r) decimal32 (double __r) decimal32 (long double __r) decimal32 (int __z) decimal32 (unsigned int __z) decimal32 (long __z) decimal32 (unsigned long __z) decimal32 (long long __z) decimal32 (unsigned long long __z) decimal32 (__decfloat32 __z)…
std::decimal::decimal128 – Synopsis Public Types typedef float __decfloat128 __attribute__ ((mode(TD))) Public Member Functions decimal128 (decimal32 d32) decimal128 (decimal64 d64) decimal128 (float __r) decimal128 (double __r) decimal128 (long double __r) decimal128 (int __z) decimal128 (unsigned int __z) decimal128 (long __z) decimal128 (unsigned long __z) decimal128 (long long __z) decimal128 (unsigned long long __z) decimal128 (__decfloat128 __z)…
std::decimal – Synopsis Classes class decimal128 class decimal32 class decimal64 Functions double decimal128_to_double (decimal128 __d) float decimal128_to_float (decimal128 __d) long double decimal128_to_long_double (decimal128 __d) long long decimal128_to_long_long (decimal128 __d) double decimal32_to_double (decimal32 __d) float decimal32_to_float (decimal32 __d) long double decimal32_to_long_double (decimal32 __d) long long decimal32_to_long_long (decimal32 __d) double decimal64_to_double (decimal64 __d) float decimal64_to_float (decimal64 __d)…
std::decay – std::decay Synopsis Defined in header<type_traits> template <class T> (since C++ 11) struct decay; Applies lvalue-to-rvalue, array-to-pointer, and function-to-pointer implicit conversions to the type T, removes cv-qualifiers, and defines the resulting type as the member typedef type. Formally: * If T names the type "array of U" or "reference to array of U", the…
std::dec,std::hex,std::oct – std::dec,std::hex,std::oct Synopsis Defined in header <ios> std::ios_base& dec( std::ios_base& str ); (1) std::ios_base& hex( std::ios_base& str ); (2) std::ios_base& oct( std::ios_base& str ); (3) Modifies the default numeric base for integer I/O. 1) sets the basefield of the stream str to dec as if by calling str.setf(std::ios_base::dec, std::ios_base::basefield) 2) sets the basefield of…
std::data – std::data Synopsis Defined in header<iterator> template <class C> (1)(since C++ 17) constexpr auto data(C &c) -> decltype(c.data()); template <class C> (2)(since C++ 17) constexpr auto data(const C &c) -> decltype(c.data()); template <class T, std::size_t N> (3)(since C++ 17) constexpr T *data(T (&array)[N]) noexcept; template <class E> (4)(since C++ 17) constexpr const E *data(std::initializer_list<E>…
std::cyl_neumann,std::cyl_neumannf,std::cyl_neumannl – std::cyl_neumann,std::cyl_neumannf,std::cyl_neumannl Synopsis double cyl_neumann( double ν, double x ); float cyl_neumannf( float ν, float x ); (1) (since C++17) long double cyl_neumannl( long double ν, long double x ); Promoted cyl_neumann( Arithmetic ν, Arithmetic x ); (2) (since C++17) 1) Computes the cylindrical_Neumann_function (also known as Bessel function of the second kind or…
std::cyl_bessel_k,std::cyl_bessel_kf,std::cyl_bessel_kl – std::cyl_bessel_k,std::cyl_bessel_kf,std::cyl_bessel_kl Synopsis double cyl_bessel_k( double ν, double x ); float cyl_bessel_kf( float ν, float x ); (1) (since C++17) long double cyl_bessel_kl( long double ν, long double x ); Promoted cyl_bessel_k( Arithmetic ν, Arithmetic x ); (2) (since C++17) 1) Computes the irregular_modified_cylindrical_Bessel_function (also known as modified Bessel function of the second kind)…
std::cyl_bessel_j,std::cyl_bessel_jf,std::cyl_bessel_jl – std::cyl_bessel_j,std::cyl_bessel_jf,std::cyl_bessel_jl Synopsis double cyl_bessel_j( double ν, double x ); float cyl_bessel_jf( float ν, float x ); (1) (since C++17) long double cyl_bessel_jl( long double ν, long double x ); Promoted cyl_bessel_j( Arithmetic ν, Arithmetic x ); (2) (since C++17) 1) Computes the cylindrical_Bessel_function_of_the_first_kind of ν and x. 2) A set of overloads or…