std::basic_string::swap

 

C++

Language

Standard library headers

Concepts

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

 

Strings library

Null-terminated strings

Byte strings

Multibyte strings

Wide strings

Classes

basic_string

basic_string_view (C++17)

char_traits

 

std::basic_string

Member functions basic_string::basic_string basic_string::operator= basic_string::assign basic_string::get_allocator Element access basic_string::at basic_string::operator[] basic_string::front (C++11) basic_string::back (C++11) basic_string::data basic_string::c_str basic_string::operator basic_string_view (C++17) Iterators basic_string::beginbasic_string::cbegin (C++11) basic_string::endbasic_string::cend (C++11) basic_string::rbeginbasic_string::crbegin (C++11) basic_string::rendbasic_string::crend (C++11) Capacity basic_string::empty basic_string::sizebasic_string::length basic_string::max_size basic_string::reserve basic_string::capacity basic_string::shrink_to_fit (C++11)

Operations basic_string::clear basic_string::insert basic_string::erase basic_string::push_back basic_string::pop_back (C++11) basic_string::append basic_string::operator+= basic_string::compare basic_string::replace basic_string::substr basic_string::copy basic_string::resize basic_string::swap Search basic_string::find basic_string::rfind basic_string::find_first_of basic_string::find_first_not_of basic_string::find_last_of basic_string::find_last_not_of Constants basic_string::npos

Non-member functions operator+ operator==operator!=operator<operator>operator<=operator>= swap(std::basic_string) operator<<operator>> getline stoistolstoll (C++11)(C++11)(C++11) stoulstoull (C++11)(C++11) stofstodstold (C++11)(C++11)(C++11) to_string (C++11) to_wstring (C++11) operator""s (C++14) Helper classes hash<std::string>hash<std::wstring>hash<std::u32string>hash<std::u16string> (C++11)(C++11)(C++11)(C++11)

 

void swap( basic_string& other );		(until C++17)
void swap( basic_string& other ) noexcept(/* see below */);		(since C++17)

Exchanges the contents of the string with those of other. All iterators and references may be invalidated.

Parameters

other

-

string to exchange the contents with

Return value

(none)

Exceptions noexcept specification:   noexcept(std::allocator_traits<Allocator>::propagate_on_container_swap::value || std::allocator_traits<Allocator>::is_always_equal::value)

(since C++17)

Example

Run this code

#include <string>
#include <iostream>
 
int main() 
{
    std::string a = "AAA";
    std::string b = "BBB";
 
    std::cout << "before swap" << '\n';
    std::cout << "a: " << a << '\n';
    std::cout << "b: " << b << '\n';
 
    a.swap(b);
 
    std::cout << "after swap" << '\n';
    std::cout << "a: " << a << '\n';
    std::cout << "b: " << b << '\n';
}

Output:

before swap
a: AAA
b: BBB
after swap
a: BBB
b: AAA

Complexity

Constant.