deduction guides for std::array

 

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Containers library

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array (C++11)

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unordered_set (C++11)

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stack

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span (C++20)

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std::array

Member types
Member functions
Element access array::at array::operator[]    array::front array::back array::data Operations array::fill array::swap	Iterators array::beginarray::cbegin array::endarray::cend array::rbeginarray::crbegin    array::rendarray::crend	Capacity array::empty array::size array::max_size
Non-member functions
operator==operator<=> (C++20) get(std::array) swap(std::array) to_array (C++20)	operator|=operator<operator>operator<=operator>= (until C++20)(until C++20)(until C++20)(until C++20)(until C++20)
Helper classes
tuple_size<std::array>
tuple_element<std::array>
Deduction guides (C++17)

 

Defined in header <array>
template< class T, class... U > array( T, U... )   -> array<T, 1 + sizeof...(U)>;		(since C++17)

One deduction guide is provided for std::array to provide an equivalent of std::experimental::make_array for construction of std::array from a variadic parameter pack.

The program is ill-formed if (std::is_same_v<T, U> && ...) is not true. Note that (std::is_same_v<T, U> && ...) is true when sizeof...(U) is zero.

Example

Run this code

#include <array>
#include <cassert>
 
int main()
{
    int const x = 10;
    std::array a{1, 2, 3, 5, x}; // OK, creates std::array<int, 5>
    assert(a.back() == x);
 
//  std::array b{1, 2u}; // Error, all arguments must have the same type
 
//  std::array<short> c{3, 2, 1}; // Error, wrong number of template args
    std::array c(std::to_array<short>({3, 2, 1})); // C++20 alternative,
                                                   // creates std::array<short, 3>
}