标准库头文件 <tuple> (C++11)

 

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标准库头文件

语言支持 <cfloat> <climits> <compare> (C++20) <contracts> (C++26) <coroutine> (C++20) <csetjmp> <csignal> <cstdarg> <cstddef> <cstdint> (C++11) <cstdlib> <exception> <initializer_list> (C++11)    <limits> <new> <source_location> (C++20) <stdfloat> (C++23) <typeinfo> <version> (C++20) 概念 <concepts> (C++20) 诊断 <cassert> <cerrno> <debugging> (C++26) <stacktrace> (C++23) <stdexcept> <system_error> (C++11) 内存管理 <memory> <memory_resource> (C++17) <scoped_allocator> (C++11) 元编程 <type_traits> (C++11) <ratio> (C++11)

通用工具 <any> (C++17) <bitset> <bit> (C++20) <charconv> (C++17) <expected> (C++23) <format> (C++20) <functional> <optional> (C++17) <tuple> (C++11) <typeindex> (C++11) <utility> <variant> (C++17) 容器 <array> (C++11) <deque> <flat_map> (C++23) <flat_set> (C++23) <forward_list> (C++11) <hive> (C++26) <inplace_vector> (C++26)    <list> <map> <mdspan> (C++23) <queue> <set> <span> (C++20) <stack> <unordered_map> (C++11) <unordered_set> (C++11) <vector> 迭代器 <iterator> 范围 <generator> (C++23) <ranges> (C++20)

算法 <algorithm> <numeric> 字符串 <cctype> <cstring> <cuchar> (C++11) <cwchar> <cwctype> <string_view> (C++17) <string> 文本处理 <clocale> <codecvt> (C++11/17/26*) <locale> <regex> (C++11) <text_encoding> (C++26)    数值 <cfenv> (C++11) <cmath> <complex> <linalg> (C++26) <numbers> (C++20) <random> (C++11) <simd> (C++26) <valarray> 时间 <chrono> (C++11) <ctime> C 兼容性 <ccomplex> (C++11/17/20*) <ciso646> (直到 C++20) <cstdalign> (C++11/17/20*) <cstdbool> (C++11/17/20*) <ctgmath> (C++11/17/20*)

输入/输出 <cinttypes> (C++11) <cstdio> <filesystem> (C++17) <fstream> <iomanip> <iosfwd> <iostream> <ios> <istream> <ostream> <print> (C++23) <spanstream> (C++23) <sstream> <streambuf> <strstream> (C++98/26*) <syncstream> (C++20) 并发支持 <atomic> (C++11) <barrier> (C++20) <condition_variable> (C++11) <future> (C++11) <hazard_pointer> (C++26) <latch> (C++20) <mutex> (C++11) <rcu> (C++26) <semaphore> (C++20) <shared_mutex> (C++14) <stdatomic.h> (C++23) <stop_token> (C++20) <thread> (C++11) 执行支持 <execution> (C++17)

 

此头文件是通用工具库的一部分。

包含
<compare> (C++20)	三路比较运算符 支持
类
tuple (C++11)	实现固定大小的容器，用于保存可能具有不同类型的元素 (类模板)
tuple_size (C++11)	获取 tuple-like 类型的元素数量 (类模板)
tuple_element (C++11)	获取 tuple-like 类型的元素类型 (类模板)
std::tuple_size<std::tuple> (C++11)	获取大小 一个 tuple (类模板特化)
std::tuple_element<std::tuple> (C++11)	获取指定元素的类型 (类模板特化)
std::uses_allocator<std::tuple> (C++11)	特化 std::uses_allocator 类型特征 (类模板特化)
常量
ignore (C++11)	在使用 tie 解包 tuple 时跳过元素的占位符 (常量)
函数
make_tuple (C++11)	创建由参数类型定义的类型的 tuple 对象 (函数模板)
tie (C++11)	创建左值引用 tuple 或将 tuple 解包到单独的对象中 (函数模板)
forward_as_tuple (C++11)	创建 转发引用 的 tuple (函数模板)
tuple_cat (C++11)	通过连接任意数量的 tuple 来创建 tuple (函数模板)
get(std::tuple) (C++11)	tuple 访问指定的元素 (函数模板)
operator==operator!=operator<operator<=operator>operator>=operator<=> (在 C++20 中移除)(在 C++20 中移除)(在 C++20 中移除)(在 C++20 中移除)(在 C++20 中移除)(C++20)	按字典顺序比较 tuple 中的值 (函数模板)
std::swap(std::tuple) (C++11)	特化 std::swap 算法 (函数模板)
apply (C++17)	使用 tuple 参数调用函数 (函数模板)
make_from_tuple (C++17)	使用 tuple 参数构造对象 (函数模板)

概要

#include <compare>
 
namespace std {
  // class template tuple
  template<class... Types>
    class tuple;
 
  // tuple creation functions
  inline constexpr /* unspecified */ ignore;
 
  template<class... TTypes>
    constexpr tuple<unwrap_ref_decay_t<TTypes>...> make_tuple(TTypes&&...);
 
  template<class... TTypes>
    constexpr tuple<TTypes&&...> forward_as_tuple(TTypes&&...) noexcept;
 
  template<class... TTypes>
    constexpr tuple<TTypes&...> tie(TTypes&...) noexcept;
 
  template<class... Tuples>
    constexpr tuple<CTypes...> tuple_cat(Tuples&&...);
 
  // calling a function with a tuple of arguments
  template<class F, class Tuple>
    constexpr decltype(auto) apply(F&& f, Tuple&& t);
 
  template<class T, class Tuple>
    constexpr T make_from_tuple(Tuple&& t);
 
  // tuple helper classes
  template<class T> struct tuple_size;                  // not defined
  template<class T> struct tuple_size<const T>;
 
  template<class... Types> struct tuple_size<tuple<Types...>>;
 
  template<size_t I, class T> struct tuple_element;     // not defined
  template<size_t I, class T> struct tuple_element<I, const T>;
 
  template<size_t I, class... Types>
    struct tuple_element<I, tuple<Types...>>;
 
  template<size_t I, class T>
    using tuple_element_t = typename tuple_element<I, T>::type;
 
  // element access
  template<size_t I, class... Types>
    constexpr tuple_element_t<I, tuple<Types...>>& get(tuple<Types...>&) noexcept;
  template<size_t I, class... Types>
    constexpr tuple_element_t<I, tuple<Types...>>&& get(tuple<Types...>&&) noexcept;
  template<size_t I, class... Types>
    constexpr const tuple_element_t<I, tuple<Types...>>&
      get(const tuple<Types...>&) noexcept;
  template<size_t I, class... Types>
    constexpr const tuple_element_t<I, tuple<Types...>>&&
      get(const tuple<Types...>&&) noexcept;
  template<class T, class... Types>
    constexpr T& get(tuple<Types...>& t) noexcept;
  template<class T, class... Types>
    constexpr T&& get(tuple<Types...>&& t) noexcept;
  template<class T, class... Types>
    constexpr const T& get(const tuple<Types...>& t) noexcept;
  template<class T, class... Types>
    constexpr const T&& get(const tuple<Types...>&& t) noexcept;
 
  // relational operators
  template<class... TTypes, class... UTypes>
    constexpr bool operator==(const tuple<TTypes...>&, const tuple<UTypes...>&);
  template<class... TTypes, class... UTypes>
    constexpr common_comparison_category_t</*synth-three-way-result*/<TTypes, UTypes>...>
      operator<=>(const tuple<TTypes...>&, const tuple<UTypes...>&);
 
  // allocator-related traits
  template<class... Types, class Alloc>
    struct uses_allocator<tuple<Types...>, Alloc>;
 
  // specialized algorithms
  template<class... Types>
    constexpr void
      swap(tuple<Types...>& x, tuple<Types...>& y) noexcept(/* see description */);
 
  // tuple helper classes
  template<class T>
    inline constexpr size_t tuple_size_v = tuple_size<T>::value;
}
 
// deprecated
namespace std {
  template<class T> class tuple_size<volatile T>;
  template<class T> class tuple_size<const volatile T>;
 
  template<size_t I, class T> class tuple_element<I, volatile T>;
  template<size_t I, class T> class tuple_element<I, const volatile T>;
}

类模板 std::tuple

namespace std {
  template<class... Types>
  class tuple {
  public:
    // tuple construction
    constexpr explicit(/* see description */) tuple();
    constexpr explicit(/* see description */)
      tuple(const Types&...);         // only if sizeof...(Types) >= 1
    template<class... UTypes>
      constexpr explicit(/* see description */)
        tuple(UTypes&&...);           // only if sizeof...(Types) >= 1
 
    tuple(const tuple&) = default;
    tuple(tuple&&) = default;
 
    template<class... UTypes>
      constexpr explicit(/* see description */) tuple(const tuple<UTypes...>&);
    template<class... UTypes>
      constexpr explicit(/* see description */) tuple(tuple<UTypes...>&&);
 
    template<class U1, class U2>
      constexpr explicit(/* see description */)
        tuple(const pair<U1, U2>&);   // only if sizeof...(Types) == 2
    template<class U1, class U2>
      constexpr explicit(/* see description */)
        tuple(pair<U1, U2>&&);        // only if sizeof...(Types) == 2
 
    // allocator-extended constructors
    template<class Alloc>
      constexpr explicit(/* see description */)
        tuple(allocator_arg_t, const Alloc& a);
    template<class Alloc>
      constexpr explicit(/* see description */)
        tuple(allocator_arg_t, const Alloc& a, const Types&...);
    template<class Alloc, class... UTypes>
      constexpr explicit(/* see description */)
        tuple(allocator_arg_t, const Alloc& a, UTypes&&...);
    template<class Alloc>
      constexpr tuple(allocator_arg_t, const Alloc& a, const tuple&);
    template<class Alloc>
      constexpr tuple(allocator_arg_t, const Alloc& a, tuple&&);
    template<class Alloc, class... UTypes>
      constexpr explicit(/* see description */)
        tuple(allocator_arg_t, const Alloc& a, const tuple<UTypes...>&);
    template<class Alloc, class... UTypes>
      constexpr explicit(/* see description */)
        tuple(allocator_arg_t, const Alloc& a, tuple<UTypes...>&&);
    template<class Alloc, class U1, class U2>
      constexpr explicit(/* see description */)
        tuple(allocator_arg_t, const Alloc& a, const pair<U1, U2>&);
    template<class Alloc, class U1, class U2>
      constexpr explicit(/* see description */)
        tuple(allocator_arg_t, const Alloc& a, pair<U1, U2>&&);
 
    // tuple assignment
    constexpr tuple& operator=(const tuple&);
    constexpr tuple& operator=(tuple&&) noexcept(/* see description */);
 
    template<class... UTypes>
      constexpr tuple& operator=(const tuple<UTypes...>&);
    template<class... UTypes>
      constexpr tuple& operator=(tuple<UTypes...>&&);
 
    template<class U1, class U2>
      constexpr tuple& operator=(const pair<U1, U2>&); // only if sizeof...(Types) == 2
    template<class U1, class U2>
      constexpr tuple& operator=(pair<U1, U2>&&);      // only if sizeof...(Types) == 2
 
    // tuple swap
    constexpr void swap(tuple&) noexcept(/* see description */);
  };
 
  template<class... UTypes>
    tuple(UTypes...) -> tuple<UTypes...>;
  template<class T1, class T2>
    tuple(pair<T1, T2>) -> tuple<T1, T2>;
  template<class Alloc, class... UTypes>
    tuple(allocator_arg_t, Alloc, UTypes...) -> tuple<UTypes...>;
  template<class Alloc, class T1, class T2>
    tuple(allocator_arg_t, Alloc, pair<T1, T2>) -> tuple<T1, T2>;
  template<class Alloc, class... UTypes>
    tuple(allocator_arg_t, Alloc, tuple<UTypes...>) -> tuple<UTypes...>;
}