Section 3: library functions
std::ratio_equal – std::ratio_equal Synopsis Defined in header<ratio> template <class R1, class R2> (since C++ 11) struct ratio_equal : std::integral_constant; If the ratios R1 and R2 are equal, provides the member constant value equal true. Otherwise, value is false. Helper variable template template< class R1, class R2 > (since C++17) inline constexpr bool ratio_equal_v = ratio_equal<R1,…
std::ratio_divide – std::ratio_divide Synopsis Defined in header <ratio> template< class R1, class R2 > (since C++11) using ratio_divide = /* see below */; The alias template std::ratio_divide denotes the result of dividing two exact rational fractions represented by the std::ratio specializations R1 and R2. The result is a std::ratio specialization std::ratio<U, V>, such that given…
std::ratio_add – std::ratio_add Synopsis Defined in header <ratio> template< class R1, class R2 > (since C++11) using ratio_add = /* see below */; The alias template std::ratio_add denotes the result of adding two exact rational fractions represented by the std::ratio specializations R1 and R2. The result is a std::ratio specialization std::ratio<U, V>, such that given…
std::ratio – std::ratio Synopsis Defined in header <ratio> template< std::intmax_t Num, (since C++11) std::intmax_t Denom = 1 > class ratio; The class template std::ratio provides compile-time_rational_arithmetic support. Each instantiation of this template exactly represents any finite rational number as long as its numerator Num and denominator Denom are representable as compile-time constants of type std::intmax_t….
std::rank – std::rank Synopsis Defined in header<type_traits> template <class T> (since C++ 11) struct rank; If T is an array type, provides the member constant value equal to the number of dimensions of the array. For any other type, value is 0. Helper variable template template< class T > (since C++17) inline constexpr std::size_t rank_v…
std::ranges::view::reverse,std::ranges::reverse_view – std::ranges::view::reverse,std::ranges::reverse_view Synopsis template< View V > requires BidirectionalRange<V> (1) (since C++20) class reverse_view : public ranges::view_interface<reverse_view<V>> namespace view { inline constexpr /*unspecified*/ reverse = /*unspecified*/; (2) (since C++20) } 1) A range adaptor that represents a view of underlying View with reversed order. 2) The expression view::reverse(E) is expression-equivalent to (has the same…
std::ranges::view::iota,std::ranges::iota_view – std::ranges::view::iota,std::ranges::iota_view Synopsis template<WeaklyIncrementable W, Semiregular Bound = unreachable_sentinel_t> requires _WeaklyEqualityComparableWith<W, Bound> (1) (since C++20) class iota_view : public view_interface<iota_view<W, Bound>> namespace view { inline constexpr /*unspecified*/ iota = /*unspecified*/; (2) (since C++20) } 1) A range factory that generates a sequence of elements by repeatedly incrementing an initial value. Can be both bounded…
std::ranges::view::filter,std::ranges::filter_view – std::ranges::view::filter,std::ranges::filter_view Synopsis template< InputRange V, IndirectUnaryPredicate<iterator_t<V>> Pred > requires View<V> && std::is_object_v<Pred> (1) (since C++20) class filter_view : public ranges::view_interface<filter_view<V, Pred>> namespace view { inline constexpr /*unspecified*/ filter = /*unspecified*/; (2) (since C++20) } 1) A range adaptor that represents View of an underlying sequence without the elements that fail to satisfy a…
std::ranges::view::empty,std::ranges::empty_view – std::ranges::view::empty,std::ranges::empty_view Synopsis template<class T> requires is_object_v<T> (1) (since C++20) class empty_view : public view_interface<empty_view<T>> namespace view { template<class T> inline constexpr empty_view<T> empty{}; (2) (since C++20) } 1) A range adaptor that produces a View of no elements of a particular type. 2) Variable template for empty_view. Member functions std::ranges::empty_view::begin static constexpr T*…
std::ranges::view::counted – std::ranges::view::counted Synopsis namespace view { inline constexpr /*unspecified*/ counted = /*unspecified*/; (since C++20) } A counted view presents a View of the elements of the counted range [i, n) for some iterator i and non-negative integer n. A counted range [i, n) is the n elements starting with the element pointed to by…
std::ranges::view::all,std::ranges::all_view – std::ranges::view::all,std::ranges::all_view Synopsis template <ViewableRange R> (1) (since C++20) using all_view = decltype(view::all(std::declval<R>())); namespace view { inline constexpr /*unspecified*/ all = /*unspecified*/; (2) (since C++20) } A range adaptor that returns a View that includes all elements of its Range argument. The expression view::all(E) is expression-equivalent (has the same effect) to: *decay – copy(E)…
std::ranges::swap – std::ranges::swap Synopsis Defined in header<concepts> inline namespace /* unspecified */ { (since C++ 20) inline constexpr /* unspecified */ swap = /* unspecified */; (customization point object) } Call signature template <class T, class U> requires /* see below */ constexpr void swap(T &&t, U &&u) noexcept(/* see below */); Exchanges the values…
std::ranges::safe_iterator_t,std::ranges::safe_subrange_t – std::ranges::safe_iterator_t,std::ranges::safe_subrange_t Synopsis Defined in header <ranges> template<Range R> using safe_iterator_t = std::conditional_t<__ForwardingRange<R>, (1) (since C++20) ranges::iterator_t<R>, ranges::dangling>; template<Range R> using safe_subrange_t = std::conditional_t<__ForwardingRange<R>, (2) (since C++20) ranges::subrange<ranges::iterator_t<R>>, ranges::dangling>; 1) Same as ranges::iterator_t when R models exposition-only concept __ForwardingRange, otherwise yields ranges::dangling instead. 2) Similar to (1), but it yields a specialization of ranges::subrange…
std::ranges::ref_view – std::ranges::ref_view Synopsis Defined in header <ranges> template<Range R> requires std::is_object_v<R> (since C++20) class ref_view : public ranges::view_interface<ref_view<R>> ref_Âview is a View of the elements of some other Range. It wraps a reference to that Range. Data members std::ranges::ref_view::r_ R* r_ = nullptr; /* exposition-only */ pointer to the referenced range Member functions std::ranges::ref_view::ref_view…
std::ranges::not_equal_to – std::ranges::not_equal_to Synopsis Defined in header <functional> struct not_equal_to; (since C++20) Function object for performing comparisons. Deduces the parameter types of the function call operator from the arguments (but not the return type). Member types Member type Definition is_transparent /* unspecified */ Member functions checks if the arguments are not equal operator() (public member…
std::ranges::less_equal – std::ranges::less_equal Synopsis Defined in header <functional> struct less_equal; (since C++20) Function object for performing comparisons. Deduces the parameter types of the function call operator from the arguments (but not the return type). Member types Member type Definition is_transparent /* unspecified */ Member functions checks if the first argument is less than or equal…
std::ranges::less – std::ranges::less Synopsis Defined in header <functional> struct less; (since C++20) Function object for performing comparisons. Deduces the parameter types of the function call operator from the arguments (but not the return type). Member types Member type Definition is_transparent /* unspecified */ Member functions checks if the first argument is less than the second…
std::ranges::iterator_t,std::ranges::sentinel_t – std::ranges::iterator_t,std::ranges::sentinel_t Synopsis Defined in header <ranges> template <class T> (1) (since C++20) using iterator_t = decltype(ranges::begin(declval<T&>())); template <class T> (2) (since C++20) using sentinel_t = decltype(ranges::end(declval<T&>())); 1) Used to obtain the iterator type of the type T. 2) Used to obtain the sentinel type of the type T.
std::ranges::greater_equal – std::ranges::greater_equal Synopsis Defined in header <functional> struct greater_equal; (since C++20) Function object for performing comparisons. Deduces the parameter types of the function call operator from the arguments (but not the return type). Member types Member type Definition is_transparent /* unspecified */ Member functions checks if the first argument is greater than or equal…
std::ranges::greater – std::ranges::greater Synopsis Defined in header <functional> struct greater; (since C++20) Function object for performing comparisons. Deduces the parameter types of the function call operator from the arguments (but not the return type). Member types Member type Definition is_transparent /* unspecified */ Member functions checks if the first argument is greater than the second…