标准库标头 <array> (C++11) - cppreference.com

标准库标头 <array> (C++11)

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C++
 
标准库头
通用工具
<any> (C++17)
<bitset>
<bit> (C++20)
<charconv> (C++17)
<expected> (C++23)
<format> (C++20)
<functional>
<optional> (C++17)
<stdbit.h> (C++26)
<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)
 

此头文件是容器库的一部分。

概要

// 大多数为独立
#include <compare>
#include <initializer_list>

namespace std {
  // 类模板 array
  template<class T, size_t N>
  struct array; // 部分独立

  template<class T, size_t N>
  constexpr bool operator==(const array<T, N>& x, const array<T, N>& y);
  template<class T, size_t N>
  constexpr /*synth-three-way-result*/<T> operator<=>(const array<T, N>& x,
                                                      const array<T, N>& y);

  // 特化的算法
  template<class T, size_t N>
  constexpr void swap(array<T, N>& x, array<T, N>& y) noexcept(noexcept(x.swap(y)));

  // array 创建函数
  template<class T, size_t N>
  constexpr array<remove_cv_t<T>, N> to_array(T (&a)[N]);
  template<class T, size_t N>
  constexpr array<remove_cv_t<T>, N> to_array(T (&&a)[N]);

  // tuple 接口
  template<class T>
  struct tuple_size;
  template<size_t I, class T>
  struct tuple_element;
  template<class T, size_t N>
  struct tuple_size<array<T, N>>;
  template<size_t I, class T, size_t N>
  struct tuple_element<I, array<T, N>>;
  template<size_t I, class T, size_t N>
  constexpr T& get(array<T, N>&) noexcept;
  template<size_t I, class T, size_t N>
  constexpr T&& get(array<T, N>&&) noexcept;
  template<size_t I, class T, size_t N>
  constexpr const T& get(const array<T, N>&) noexcept;
  template<size_t I, class T, size_t N>
  constexpr const T&& get(const array<T, N>&&) noexcept;
}

类模板 std::array

namespace std {
  template<class T, size_t N>
  struct array
  {
    // 类型
    using value_type             = T;
    using pointer                = T*;
    using const_pointer          = const T*;
    using reference              = T&;
    using const_reference        = const T&;
    using size_type              = size_t;
    using difference_type        = ptrdiff_t;
    using iterator               = /* 由实现定义 */;
    using const_iterator         = /* 由实现定义 */;
    using reverse_iterator       = std::reverse_iterator<iterator>;
    using const_reverse_iterator = std::reverse_iterator<const_iterator>;

    // 聚合类型无显式的构造/复制/销毁

    constexpr void fill(const T& u);
    constexpr void swap(array&) noexcept(is_nothrow_swappable_v<T>);

    // 迭代器
    constexpr iterator begin() noexcept;
    constexpr const_iterator begin() const noexcept;
    constexpr iterator end() noexcept;
    constexpr const_iterator end() const noexcept;

    constexpr reverse_iterator rbegin() noexcept;
    constexpr const_reverse_iterator rbegin() const noexcept;
    constexpr reverse_iterator rend() noexcept;
    constexpr const_reverse_iterator rend() const noexcept;

    constexpr const_iterator cbegin() const noexcept;
    constexpr const_iterator cend() const noexcept;
    constexpr const_reverse_iterator crbegin() const noexcept;
    constexpr const_reverse_iterator crend() const noexcept;

    // 容量
    constexpr bool empty() const noexcept;
    constexpr size_type size() const noexcept;
    constexpr size_type max_size() const noexcept;

    // 元素访问
    constexpr reference operator[](size_type n);
    constexpr const_reference operator[](size_type n) const;
    constexpr reference at(size_type n);             // 独立环境删除
    constexpr const_reference at(size_type n) const; // 独立环境删除
    constexpr reference front();
    constexpr const_reference front() const;
    constexpr reference back();
    constexpr const_reference back() const;

    constexpr T* data() noexcept;
    constexpr const T* data() const noexcept;
  };

  template<class T, class... U>
  array(T, U...) -> array<T, 1 + sizeof...(U)>;
}