std::vector<bool,Allocator>::swap
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< cpp | container | vector bool
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vector<bool>::swap
(C++20)
(C++20)(C++20)
(until C++20)(until C++20)(until C++20)(until C++20)(until C++20)
(C++11)
Defined in header
<vector>
static void swap( reference x, reference y );
(constexpr since C++20)
Swaps the contents of x and y as if by bool b = x; x = y; y = b;.
[edit] Parameters
[edit] Return value
(none)
[edit] Complexity
Constant.
[edit] 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
[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 814 | C++98 | the description of this member function was missing | added |