Standard library header <array> (C++11)

 

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Standard library headers

Language support <cfloat> <climits> <compare> (C++20) <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) Concepts <concepts> (C++20) Diagnostics <cassert> <cerrno> <debugging> (C++26) <stacktrace> (C++23) <stdexcept> <system_error> (C++11) Memory management <memory> <memory_resource> (C++17) <scoped_allocator> (C++11) Metaprogramming <type_traits> (C++11) <ratio> (C++11)

General utilities <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) Containers <array> (C++11) <deque> <flat_map> (C++23) <flat_set> (C++23) <forward_list> (C++11) <inplace_vector> (C++26)    <list> <map> <mdspan> (C++23) <queue> <set> <span> (C++20) <stack> <unordered_map> (C++11) <unordered_set> (C++11) <vector> Iterators <iterator> Ranges <generator> (C++23) <ranges> (C++20)

Algorithms <algorithm> <numeric> Strings <cctype> <cstring> <cuchar> (C++11) <cwchar> <cwctype> <string_view> (C++17) <string> Text processing <clocale> <codecvt> (C++11/17/26*) <locale> <regex> (C++11) <text_encoding> (C++26)    Numerics <cfenv> (C++11) <cmath> <complex> <linalg> (C++26) <numbers> (C++20) <random> (C++11) <valarray> Time <chrono> (C++11) <ctime> C compatibility <ccomplex> (C++11/17/20*) <ciso646> (until C++20) <cstdalign> (C++11/17/20*) <cstdbool> (C++11/17/20*) <ctgmath> (C++11/17/20*)

Input/output <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) Concurrency support <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) Execution support <execution> (C++17)

 

This header is part of the containers library.

Includes
<compare> (C++20)	Three-way comparison operator support
<initializer_list> (C++11)	std::initializer_list class template
Classes
array (C++11)	fixed-sized inplace contiguous array (class template)
tuple_size (C++11)	obtains the number of elements of a tuple-like type (class template)
tuple_element (C++11)	obtains the element types of a tuple-like type (class template)
std::tuple_size<std::array> (C++11)	obtains the size of an array (class template specialization)
std::tuple_element<std::array> (C++11)	obtains the type of the elements of array (class template specialization)
Functions
operator==operator!=operator<operator<=operator>operator>=operator<=> (C++11)(C++11)(removed in C++20)(C++11)(removed in C++20)(C++11)(removed in C++20)(C++11)(removed in C++20)(C++11)(removed in C++20)(C++20)	lexicographically compares the values of two arrays (function template)
std::swap(std::array) (C++11)	specializes the std::swap algorithm (function template)
to_array (C++20)	creates a std::array object from a built-in array (function template)
get(std::array) (C++11)	accesses an element of an array (function template)
Range access
begincbegin (C++11)(C++14)	returns an iterator to the beginning of a container or array (function template)
endcend (C++11)(C++14)	returns an iterator to the end of a container or array (function template)
rbegincrbegin (C++14)	returns a reverse iterator to the beginning of a container or array (function template)
rendcrend (C++14)	returns a reverse end iterator for a container or array (function template)
sizessize (C++17)(C++20)	returns the size of a container or array (function template)
empty (C++17)	checks whether the container is empty (function template)
data (C++17)	obtains the pointer to the underlying array (function template)

Synopsis

// mostly freestanding
#include <compare>
#include <initializer_list>
 
namespace std {
  // class template array
  template<class T, size_t N>
  struct array; // partially freestanding
 
  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);
 
  // specialized algorithms
  template<class T, size_t N>
  constexpr void swap(array<T, N>& x, array<T, N>& y) noexcept(noexcept(x.swap(y)));
 
  // array creation functions
  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 interface
  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;
}

Class template std::array

namespace std {
  template<class T, size_t N>
  struct array
  {
    // types
    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               = /* implementation-defined */;
    using const_iterator         = /* implementation-defined */;
    using reverse_iterator       = std::reverse_iterator<iterator>;
    using const_reverse_iterator = std::reverse_iterator<const_iterator>;
 
    // no explicit construct/copy/destroy for aggregate type
 
    constexpr void fill(const T& u);
    constexpr void swap(array&) noexcept(is_nothrow_swappable_v<T>);
 
    // iterators
    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;
 
    // capacity
    constexpr bool empty() const noexcept;
    constexpr size_type size() const noexcept;
    constexpr size_type max_size() const noexcept;
 
    // element access
    constexpr reference operator[](size_type n);
    constexpr const_reference operator[](size_type n) const;
    constexpr reference at(size_type n);             // freestanding-deleted
    constexpr const_reference at(size_type n) const; // freestanding-deleted
    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)>;
}