27 Strings library [strings]

27.4 String classes [string.classes]

27.4.3 Class template basic_string [basic.string]

27.4.3.7 Modifiers [string.modifiers]

27.4.3.7.8 basic_string::swap [string.swap]

constexpr void swap(basic_string& s)
  noexcept(allocator_traits<Allocator>::propagate_on_container_swap::value ||
           allocator_traits<Allocator>::is_always_equal::value);

Preconditions: allocator_traits<Allocator>::propagate_on_container_swap::value is true or get_allocator() == s.get_allocator().

Postconditions: *this contains the same sequence of characters that was in s, s contains the same sequence of characters that was in *this.

Throws: Nothing.

Complexity: Constant time.