Difference between revisions of "cpp/header/utility"
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This header is part of the [[cpp/utility|general utility]] library. | This header is part of the [[cpp/utility|general utility]] library. | ||
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{{dsc begin}} | {{dsc begin}} | ||
{{dsc h1|Includes}} | {{dsc h1|Includes}} | ||
| − | {{dsc inc | cpp/header/dsc compare}} | + | {{dsc inc|cpp/header/dsc compare}} |
| − | {{dsc inc | cpp/header/dsc initializer_list}} | + | {{dsc inc|cpp/header/dsc initializer_list}} |
{{dsc h1|Namespaces}} | {{dsc h1|Namespaces}} | ||
| − | {{dsc | {{ttb|[[cpp/utility/rel_ops/operator_cmp|rel_ops]]}} | Provide automatic comparison operators}} | + | {{dsc|{{ttb|[[cpp/utility/rel_ops/operator_cmp|rel_ops]]}}|Provide automatic comparison operators}} |
| − | {{dsc namespace | std::rel_ops }} | + | {{dsc namespace|std::rel_ops}} |
| − | {{dsc inc | cpp/utility/rel_ops/dsc operator_cmp}} | + | {{dsc inc|cpp/utility/rel_ops/dsc operator_cmp}} |
{{dsc h1|Functions}} | {{dsc h1|Functions}} | ||
| − | {{dsc inc | cpp/algorithm/dsc swap}} | + | {{dsc inc|cpp/algorithm/dsc swap}} |
| − | {{dsc inc | cpp/utility/dsc exchange}} | + | {{dsc inc|cpp/utility/dsc exchange}} |
| − | {{dsc inc | cpp/utility/dsc forward}} | + | {{dsc inc|cpp/utility/dsc forward}} |
| − | {{dsc inc | cpp/utility/dsc forward_like}} | + | {{dsc inc|cpp/utility/dsc forward_like}} |
| − | {{dsc inc | cpp/utility/dsc move}} | + | {{dsc inc|cpp/utility/dsc move}} |
| − | {{dsc inc | cpp/utility/dsc move_if_noexcept}} | + | {{dsc inc|cpp/utility/dsc move_if_noexcept}} |
| − | {{dsc inc | cpp/utility/dsc as_const}} | + | {{dsc inc|cpp/utility/dsc as_const}} |
| − | {{dsc inc | cpp/utility/dsc declval}} | + | {{dsc inc|cpp/utility/dsc declval}} |
| − | {{dsc inc | cpp/utility/dsc to_underlying}} | + | {{dsc inc|cpp/utility/dsc to_underlying}} |
| − | {{dsc inc | cpp/utility/dsc intcmp}} | + | {{dsc inc|cpp/utility/dsc intcmp}} |
| − | {{dsc inc | cpp/utility/dsc in_range}} | + | {{dsc inc|cpp/utility/dsc in_range}} |
| − | {{dsc inc | cpp/utility/dsc unreachable}} | + | {{dsc inc|cpp/utility/dsc unreachable}} |
| − | {{dsc inc | cpp/utility/pair/dsc make_pair}} | + | {{dsc inc|cpp/utility/pair/dsc make_pair}} |
| − | {{dsc inc | cpp/utility/pair/dsc operator_cmp}} | + | {{dsc inc|cpp/utility/pair/dsc operator_cmp}} |
| − | {{dsc inc | cpp/utility/pair/dsc swap2}} | + | {{dsc inc|cpp/utility/pair/dsc swap2}} |
| − | {{dsc inc | cpp/utility/pair/dsc get}} | + | {{dsc inc|cpp/utility/pair/dsc get}} |
{{dsc h1|Classes}} | {{dsc h1|Classes}} | ||
| − | {{dsc inc | cpp/utility/dsc pair}} | + | {{dsc inc|cpp/utility/dsc pair}} |
| − | {{dsc inc | cpp/utility/dsc tuple_size}} | + | {{dsc inc|cpp/utility/dsc tuple_size}} |
| − | {{dsc inc | cpp/utility/dsc tuple_element}} | + | {{dsc inc|cpp/utility/dsc tuple_element}} |
| − | {{dsc inc | cpp/utility/pair/dsc tuple_size}} | + | {{dsc inc|cpp/utility/pair/dsc tuple_size}} |
| − | {{dsc inc | cpp/utility/pair/dsc tuple_element}} | + | {{dsc inc|cpp/utility/pair/dsc tuple_element}} |
| − | {{dsc inc | cpp/utility/dsc integer_sequence}} | + | {{dsc inc|cpp/utility/dsc integer_sequence}} |
{{dsc h2|Forward declarations}} | {{dsc h2|Forward declarations}} | ||
| − | {{dsc header | tuple}} | + | {{dsc header|tuple}} |
| − | {{dsc inc | cpp/utility/dsc tuple}} | + | {{dsc inc|cpp/utility/dsc tuple}} |
| − | {{dsc h1| | + | {{dsc h1|Constants}} |
| − | {{dsc inc | cpp/utility/dsc | + | {{dsc inc|cpp/utility/tuple/dsc ignore}} |
| − | {{dsc inc | cpp/utility/dsc piecewise_construct}} | + | {{dsc h1|Tags}} |
| − | {{dsc inc | cpp/utility/dsc in_place}} | + | {{dsc inc|cpp/utility/dsc piecewise_construct}} |
| + | {{dsc inc|cpp/utility/dsc in_place}} | ||
| + | {{dsc inc|cpp/utility/dsc nontype}} | ||
{{dsc end}} | {{dsc end}} | ||
===Synopsis=== | ===Synopsis=== | ||
| − | {{ | + | {{cpp/synopsis/utility}} |
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===See also=== | ===See also=== | ||
{{dsc begin}} | {{dsc begin}} | ||
| − | {{dsc inc | cpp/header/dsc tuple}} | + | {{dsc inc|cpp/header/dsc tuple}} |
{{dsc end}} | {{dsc end}} | ||
{{langlinks|de|es|ja|ru|zh}} | {{langlinks|de|es|ja|ru|zh}} | ||
Latest revision as of 13:11, 24 July 2024
This header is part of the general utility library.
Includes | ||
| (C++20) |
Three-way comparison operator support | |
| (C++11) |
std::initializer_list class template | |
Namespaces | ||
rel_ops
|
Provide automatic comparison operators | |
| Defined in namespace
std::rel_ops | ||
| (deprecated in C++20) |
automatically generates comparison operators based on user-defined operator== and operator< (function template) | |
Functions | ||
| swaps the values of two objects (function template) | ||
| (C++14) |
replaces the argument with a new value and returns its previous value (function template) | |
| (C++11) |
forwards a function argument and use the type template argument to preserve its value category (function template) | |
| (C++23) |
forwards a function argument as if casting it to the value category and constness of the expression of specified type template argument (function template) | |
| (C++11) |
converts the argument to an xvalue (function template) | |
| (C++11) |
converts the argument to an xvalue if the move constructor does not throw (function template) | |
| (C++17) |
obtains a reference to const to its argument (function template) | |
| (C++11) |
obtains a reference to an object of the template type argument for use in an unevaluated context (function template) | |
| (C++23) |
converts an enumeration to its underlying type (function template) | |
| compares two integer values, ensuring that signed negative numbers are less than unsigned numbers (function template) | ||
| (C++20) |
checks if an integer value is in the range of a given integer type (function template) | |
| (C++23) |
marks unreachable point of execution (function) | |
creates a pair object of type, determined by the argument types (function template) | ||
| (removed in C++20)(removed in C++20)(removed in C++20)(removed in C++20)(removed in C++20)(C++20) |
lexicographically compares the values in the pair (function template) | |
| (C++11) |
specializes the std::swap algorithm (function template) | |
| (C++11) |
accesses an element of a pair (function template) | |
Classes | ||
| implements binary tuple, i.e. a pair of values (class template) | ||
| (C++11) |
obtains the number of elements of a tuple-like type (class template) | |
| (C++11) |
obtains the element types of a tuple-like type (class template) | |
| (C++11) |
obtains the size of a pair (class template specialization) | |
obtains the type of the elements of pair (class template specialization) | ||
| (C++14) |
implements compile-time sequence of integers (class template) | |
Forward declarations | ||
| Defined in header
<tuple> | ||
| (C++11) |
implements fixed size container, which holds elements of possibly different types (class template) | |
Constants | ||
| (C++11) |
placeholder to skip an element when unpacking a tuple using tie (constant) | |
Tags | ||
| piecewise construction tag (tag) | ||
| in-place construction tag (tag) | ||
| (C++26) |
value construction tag (tag) | |
[edit] Synopsis
#include <compare> #include <initializer_list> namespace std { // swap template<class T> constexpr void swap(T& a, T& b) noexcept(/* see description */); template<class T, size_t N> constexpr void swap(T (&a)[N], T (&b)[N]) noexcept(is_nothrow_swappable_v<T>); // exchange template<class T, class U = T> constexpr T exchange(T& obj, U&& new_val); // forward/move template<class T> constexpr T&& forward(remove_reference_t<T>& t) noexcept; template<class T> constexpr T&& forward(remove_reference_t<T>&& t) noexcept; template<class T, class U> constexpr /* see description */ forward_like(U&& x) noexcept; template<class T> constexpr remove_reference_t<T>&& move(T&&) noexcept; template<class T> constexpr conditional_t< !is_nothrow_move_constructible_v<T> && is_copy_constructible_v<T>, const T&, T&&> move_if_noexcept(T& x) noexcept; // as_const template<class T> constexpr add_const_t<T>& as_const(T& t) noexcept; template<class T> void as_const(const T&&) = delete; // declval template<class T> add_rvalue_reference_t<T> declval() noexcept; // as unevaluated operand // integer comparison functions template<class T, class U> constexpr bool cmp_equal(T t, U u) noexcept; template<class T, class U> constexpr bool cmp_not_equal(T t, U u) noexcept; template<class T, class U> constexpr bool cmp_less(T t, U u) noexcept; template<class T, class U> constexpr bool cmp_greater(T t, U u) noexcept; template<class T, class U> constexpr bool cmp_less_equal(T t, U u) noexcept; template<class T, class U> constexpr bool cmp_greater_equal(T t, U u) noexcept; template<class R, class T> constexpr bool in_range(T t) noexcept; // to_underlying template<class T> constexpr underlying_type_t<T> to_underlying(T value) noexcept; // unreachable [[noreturn]] void unreachable(); // compile-time integer sequences template<class T, T...> struct integer_sequence; template<size_t... I> using index_sequence = integer_sequence<size_t, I...>; template<class T, T N> using make_integer_sequence = integer_sequence<T, /* see description */>; template<size_t N> using make_index_sequence = make_integer_sequence<size_t, N>; template<class... T> using index_sequence_for = make_index_sequence<sizeof...(T)>; // class template pair template<class T1, class T2> struct pair; // pair specialized algorithms template<class T1, class T2> constexpr bool operator==(const pair<T1, T2>&, const pair<T1, T2>&); template<class T1, class T2> constexpr common_comparison_category_t</*synth-three-way-result*/<T1>, /*synth-three-way-result*/<T2>> operator<=>(const pair<T1, T2>&, const pair<T1, T2>&); template<class T1, class T2> constexpr void swap(pair<T1, T2>& x, pair<T1, T2>& y) noexcept(noexcept(x.swap(y))); template<class T1, class T2> constexpr /* see description */ make_pair(T1&&, T2&&); // tuple-like access to pair template<class T> struct tuple_size; template<size_t I, class T> struct tuple_element; template<class T1, class T2> struct tuple_size<pair<T1, T2>>; template<size_t I, class T1, class T2> struct tuple_element<I, pair<T1, T2>>; template<size_t I, class T1, class T2> constexpr tuple_element_t<I, pair<T1, T2>>& get(pair<T1, T2>&) noexcept; template<size_t I, class T1, class T2> constexpr tuple_element_t<I, pair<T1, T2>>&& get(pair<T1, T2>&&) noexcept; template<size_t I, class T1, class T2> constexpr const tuple_element_t<I, pair<T1, T2>>& get(const pair<T1, T2>&) noexcept; template<size_t I, class T1, class T2> constexpr const tuple_element_t<I, pair<T1, T2>>&& get(const pair<T1, T2>&&) noexcept; template<class T1, class T2> constexpr T1& get(pair<T1, T2>& p) noexcept; template<class T1, class T2> constexpr const T1& get(const pair<T1, T2>& p) noexcept; template<class T1, class T2> constexpr T1&& get(pair<T1, T2>&& p) noexcept; template<class T1, class T2> constexpr const T1&& get(const pair<T1, T2>&& p) noexcept; template<class T2, class T1> constexpr T2& get(pair<T1, T2>& p) noexcept; template<class T2, class T1> constexpr const T2& get(const pair<T1, T2>& p) noexcept; template<class T2, class T1> constexpr T2&& get(pair<T1, T2>&& p) noexcept; template<class T2, class T1> constexpr const T2&& get(const pair<T1, T2>&& p) noexcept; // pair piecewise construction struct piecewise_construct_t { explicit piecewise_construct_t() = default; }; inline constexpr piecewise_construct_t piecewise_construct{}; template<class... Types> class tuple; // defined in <tuple> // in-place construction struct in_place_t { explicit in_place_t() = default; }; inline constexpr in_place_t in_place{}; template<class T> struct in_place_type_t { explicit in_place_type_t() = default; }; template<class T> inline constexpr in_place_type_t<T> in_place_type{}; template<size_t I> struct in_place_index_t { explicit in_place_index_t() = default; }; template<size_t I> inline constexpr in_place_index_t<I> in_place_index{}; // nontype argument tag template<auto V> struct nontype_t { explicit nontype_t() = default; }; template<auto V> inline constexpr nontype_t<V> nontype{}; } // deprecated namespace std::rel_ops { template<class T> bool operator!=(const T&, const T&); template<class T> bool operator> (const T&, const T&); template<class T> bool operator<=(const T&, const T&); template<class T> bool operator>=(const T&, const T&); }
[edit] Class template std::integer_sequence
namespace std { template<class T, T... I> struct integer_sequence { using value_type = T; static constexpr size_t size() noexcept { return sizeof...(I); } }; }
[edit] Class template std::pair
namespace std { template<class T1, class T2> struct pair { using first_type = T1; using second_type = T2; T1 first; T2 second; pair(const pair&) = default; pair(pair&&) = default; constexpr explicit(/* see description */) pair(); constexpr explicit(/* see description */) pair(const T1& x, const T2& y); template<class U1 = T1, class U2 = T2> constexpr explicit(/* see description */) pair(U1&& x, U2&& y); template<class U1, class U2> constexpr explicit(/* see description */) pair(const pair<U1, U2>& p); template<class U1, class U2> constexpr explicit(/* see description */) pair(pair<U1, U2>&& p); template<class... Args1, class... Args2> constexpr pair(piecewise_construct_t, tuple<Args1...> first_args, tuple<Args2...> second_args); constexpr pair& operator=(const pair& p); template<class U1, class U2> constexpr pair& operator=(const pair<U1, U2>& p); constexpr pair& operator=(pair&& p) noexcept(/* see description */); template<class U1, class U2> constexpr pair& operator=(pair<U1, U2>&& p); constexpr void swap(pair& p) noexcept(/* see description */); }; template<class T1, class T2> pair(T1, T2) -> pair<T1, T2>; }
[edit] See also
| (C++11) |
std::tuple class template |
