std::swap(std::basic_string)
Defined in header <string> |
||
---|---|---|
template< class CharT, class Traits, class Alloc > void swap( std::basic_string<CharT, Traits, Alloc> &lhs, std::basic_string<CharT, Traits, Alloc> &rhs ); |
(until C++17) | |
template< class CharT, class Traits, class Alloc > void swap( std::basic_string<CharT, Traits, Alloc> &lhs, std::basic_string<CharT, Traits, Alloc> &rhs ) noexcept(/* see below */); |
(since C++17) (until C++20) |
|
template< class CharT, class Traits, class Alloc > constexpr void swap( std::basic_string<CharT, Traits, Alloc> &lhs, std::basic_string<CharT, Traits, Alloc> &rhs ) noexcept(/* see below */); |
(since C++20) |
Specializes the std::swap
algorithm for std::basic_string
. Swaps the contents of lhs
and rhs
. Equivalent to lhs.swap(rhs)
.
Parameters
lhs, rhs | - | strings whose contents to swap |
Return value
(none).
Complexity
Constant.
Exceptionsnoexcept specification:
noexcept(noexcept(lhs.swap(rhs)))
|
(since C++17) |
Example
#include <string> #include <iostream> int main() { std::string a = "AAAA"; std::string b = "BBB"; std::cout << "before swap" << '\n'; std::cout << "a: " << a << '\n'; std::cout << "b: " << b << '\n'; std::swap(a,b); std::cout << "after swap" << '\n'; std::cout << "a: " << a << '\n'; std::cout << "b: " << b << '\n'; }
Output:
before swap a: AAAA b: BBB after swap a: BBB b: AAAA
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 |
See also
swaps the contents (public member function) |
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