std::array<T,N>::swap
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array::swap
(until C++20)(until C++20)(until C++20)(until C++20)(until C++20)
void swap( array& other ) noexcept(/* see below */);
(since C++11) (constexpr since C++20)
Exchanges the contents of the container with those of other. Does not cause iterators and references to associate with the other container.
Contents
[edit] Parameters
other
-
container to exchange the contents with
[edit] Return value
(none)
[edit] Exceptions
noexcept specification:
noexcept(noexcept(swap(std::declval <T&>(), std::declval <T&>())))
In the expression above, the identifier swap is looked up in the same manner as the one used by the C++17 std::is_nothrow_swappable trait.
noexcept specification:
(since C++17)noexcept(std::is_nothrow_swappable_v <T>)
noexcept specification:
noexcept
[edit] Complexity
Linear in size of the container.
[edit] Example
Run this code
#include <array> #include <iostream> template<class Os, class V> Os& operator<<(Os& os, const V& v) { os << '{'; for (auto i : v) os << ' ' << i; return os << " } "; } int main() { std::array <int, 3> a1{1, 2, 3}, a2{4, 5, 6}; auto it1 = a1.begin(); auto it2 = a2.begin(); int& ref1 = a1[1]; int& ref2 = a2[1]; std::cout << a1 << a2 << *it1 << ' ' << *it2 << ' ' << ref1 << ' ' << ref2 << '\n'; a1.swap(a2); std::cout << a1 << a2 << *it1 << ' ' << *it2 << ' ' << ref1 << ' ' << ref2 << '\n'; // Note that after swap iterators and references stay associated with their original // array, e.g. `it1` still points to element a1[0], `ref1` still refers to a1[1]. }
Output:
{ 1 2 3 } { 4 5 6 } 1 4 2 5
{ 4 5 6 } { 1 2 3 } 4 1 5 2[edit] Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| LWG 2456 | C++11 | the noexcept specification is ill-formed
|
made to work |