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std::array swap() method

// Non-const version only
constexpr void swap( array& other ) noexcept(/* see below */);

The noexcept specification for these two looks like follows:

noexcept(noexcept(swap(std::declval<T&>(), std::declval<T&>())))

Exchanges the contents of the container with those of other.

Parameters

  • other - the other array to exchange the contents with

Return value

(none)

Complexity

Linear in the size of the container.

Example

#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].
}
Possible output
{ 1 2 3 } { 4 5 6 } 1 4 2 5
{ 4 5 6 } { 1 2 3 } 4 1 5 2
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Hover to see the original license.

std::array swap() method

// Non-const version only
constexpr void swap( array& other ) noexcept(/* see below */);

The noexcept specification for these two looks like follows:

noexcept(noexcept(swap(std::declval<T&>(), std::declval<T&>())))

Exchanges the contents of the container with those of other.

Parameters

  • other - the other array to exchange the contents with

Return value

(none)

Complexity

Linear in the size of the container.

Example

#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].
}
Possible output
{ 1 2 3 } { 4 5 6 } 1 4 2 5
{ 4 5 6 } { 1 2 3 } 4 1 5 2
This article originates from this CppReference page. It was likely altered for improvements or editors' preference. Click "Edit this page" to see all changes made to this document.
Hover to see the original license.