std::priority_queue<T,Container,Compare>::swap (3) - Linux Man Pages
void swap( priority_queue& other ) noexcept(/* see below */); (since C++11)
Exchanges the contents of the container adaptor with those of other. Effectively calls using std::swap; swap(c, other.c); swap(comp, other.comp);
other - container adaptor to exchange the contents with
noexcept(noexcept(swap(c, other.c)) && noexcept(swap(comp, other.comp))) (until C++17)
In the expression above, the identifier swap is looked up in the same manner as the one used by the C++17 std::is_nothrow_swappable trait.
noexcept specification: (since C++17)
noexcept(std::is_nothrow_swappable<Container>::value && std::is_nothrow_swappable<Compare>::value)
Same as underlying container (typically constant)
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
DR Applied to Behavior as published Correct behavior
LWG_2456 C++11 the noexcept specification is ill-formed made to work
std::swap(std::priority_queue) (function template)