Home Original page

std::basic_stringbuf<CharT,Traits,Allocator>::swap - cppreference.com

From cppreference.com

void swap( basic_stringbuf& rhs );

 (since C++11)
(until C++20)

void swap( basic_stringbuf& rhs ) noexcept(/* see below */);

 (since C++20)

Swaps the state and the contents of *this and rhs.

The behavior is undefined if Allocator does not propagate on swap and the allocators of *this and other are unequal.

(since C++11)

Parameters

rhs - another basic_stringbuf

Return value

(none)

Exceptions

May throw implementation-defined exceptions.

(since C++11)
(until C++20)
noexcept

specification:

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

 (since C++20)

Notes

This function is called automatically when swapping std::stringstream objects. It is rarely necessary to call it directly.

Example

#include <iomanip>
#include <iostream>
#include <sstream>
#include <string>

int main()
{
    std::istringstream one("one");
    std::ostringstream two("two");

    std::cout << "Before swap: one = " << std::quoted(one.str())
              << ", two = " << std::quoted(two.str()) << ".\n";

    one.rdbuf()->swap(*two.rdbuf());

    std::cout << "After  swap: one = " << std::quoted(one.str())
              << ", two = " << std::quoted(two.str()) << ".\n";
}

Output: 

Before swap: one = "one", two = "two".
After  swap: one = "two", two = "one".

See also

constructs a basic_stringbuf object
(public member function) [edit]
swaps two string streams
(public member function of std::basic_stringstream<CharT,Traits,Allocator>) [edit]