std::vector<bool,Allocator>::swap
From cppreference.com
| Defined in header <vector>
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static void swap( reference x, reference y );
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(constexpr since C++20) | |
Swaps the contents of x and y as if by bool b = x; x = y; y = b;.
Parameters
| x | - | std::vector<bool>::reference value to swap with y
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| y | - | std::vector<bool>::reference value to swap with x
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Return value
(none)
Complexity
Constant.
Example
Run this code
#include <iostream>
#include <vector>
void println(std::string_view fmt, std::vector<bool> const& vb = {})
{
for (std::cout << fmt; bool const e : vb)
std::cout << e << ' ';
std::cout << '\n';
}
int main()
{
println("swap elements of the same vector:");
std::vector<bool> x{1, 0};
println("before swap, x: ", x);
x.swap(x[0], x[1]); // same as std::vector<bool>::swap(x[0], x[1]);
println("after swap, x: ", x);
println("swap elements of two different vectors:");
std::vector<bool> y{0, 0, 1};
println("before swap, x: ", x);
println("before swap, y: ", y);
y.swap(x[0], y[2]); // same as std::vector<bool>::swap(x[0], y[2]);
println("after swap, x: ", x);
println("after swap, y: ", y);
}
Output:
swap elements of the same vector:
before swap, x: 1 0
after swap, x: 0 1
swap elements of two different vectors:
before swap, x: 0 1
before swap, y: 0 0 1
after swap, x: 1 1
after swap, y: 0 0 0
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 814 | C++98 | the description of this member function was missing | added |