std::swap(std::basic_string)
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< cpp | string | basic string
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std::basic_string
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swap(std::basic_string)
(C++20)(C++20)
(until C++20)(until C++20)(until C++20)(until C++20)(until C++20)(C++20)
(C++11)(C++11)(C++11)
(C++11)(C++11)
(C++14)
(C++11)
Defined in header
<string>
template< class CharT, class Traits, class Alloc >
(until C++17)
void swap( std::basic_string <CharT, Traits, Alloc>& lhs,
template< class CharT, class Traits, class Alloc >
(since C++17) void swap( std::basic_string <CharT, Traits, Alloc>& lhs,
(constexpr since C++20)
Specializes the std::swap algorithm for std::basic_string . Swaps the contents of lhs and rhs.
Equivalent to lhs.swap(rhs).
Contents
[edit] Parameters
lhs, rhs
-
strings whose contents to swap
[edit] Return value
(none)
[edit] Complexity
Constant.
[edit] Example
Run this code
#include <iostream> #include <string> int main() { std::string a = "AAA"; std::string b = "BBBB"; std::cout << "Before swap:\n" "a = " << a << "\n" "b = " << b << "\n\n"; std::swap (a, b); std::cout << "After swap:\n" "a = " << a << "\n" "b = " << b << '\n'; }
Output:
Before swap: a = AAA b = BBBB After swap: a = BBBB b = AAA
[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 2064 | C++11 | non-member swap was noexcept and inconsistent with member swap
|
noexcept removed |