Namespaces
Variants
Views
Actions

Difference between revisions of "cpp/string/basic string/swap2"

From cppreference.com
< cpp‎ | string‎ | basic string
m (→‎Example: let the sizes be different.)
m (fmt)
Line 1: Line 1:
−
{{cpp/title | swap<small>(std::basic_string)</small>}}
+
{{cpp/title|swap<small>(std::basic_string)</small>}}
 
{{cpp/string/basic_string/navbar}}
 
{{cpp/string/basic_string/navbar}}
 
{{dcl begin}}
 
{{dcl begin}}
−
{{dcl header | string}}
+
{{dcl header|string}}
 
{{dcl rev multi
 
{{dcl rev multi
−
| until1=c++17 | dcl1=
+
|until1=c++17|dcl1=
 
template< class CharT, class Traits, class Alloc >
 
template< class CharT, class Traits, class Alloc >
−
void swap( std::basic_string<CharT, Traits, Alloc> &lhs,
+
void swap( std::basic_string<CharT, Traits, Alloc>& lhs,
−
           std::basic_string<CharT, Traits, Alloc> &rhs );
+
           std::basic_string<CharT, Traits, Alloc>& rhs );
−
| until2=c++20 | dcl2=
+
|until2=c++20|dcl2=
 
template< class CharT, class Traits, class Alloc >
 
template< class CharT, class Traits, class Alloc >
−
void swap( std::basic_string<CharT, Traits, Alloc> &lhs,
+
void swap( std::basic_string<CharT, Traits, Alloc>& lhs,
−
           std::basic_string<CharT, Traits, Alloc> &rhs ) noexcept(/* see below */);
+
           std::basic_string<CharT, Traits, Alloc>& rhs ) noexcept(/* see below */);
−
| dcl3=
+
|dcl3=
 
template< class CharT, class Traits, class Alloc >
 
template< class CharT, class Traits, class Alloc >
 
constexpr void
 
constexpr void
−
     swap( std::basic_string<CharT, Traits, Alloc> &lhs,
+
     swap( std::basic_string<CharT, Traits, Alloc>& lhs,
−
           std::basic_string<CharT, Traits, Alloc> &rhs ) noexcept(/* see below */);
+
           std::basic_string<CharT, Traits, Alloc>& rhs ) noexcept(/* see below */);
 
}}
 
}}
 
{{dcl end}}
 
{{dcl end}}
  
−
Specializes the {{lc|std::swap}} algorithm for {{lc|std::basic_string}}. Swaps the contents of {{tt|lhs}} and {{tt|rhs}}. Equivalent to {{c|lhs.swap(rhs)}}.
+
Specializes the {{lc|std::swap}} algorithm for {{lc|std::basic_string}}. Swaps the contents of {{c|lhs}} and {{c|rhs}}.
 +
 
 +
Equivalent to {{c|lhs.swap(rhs)}}.
  
 
===Parameters===
 
===Parameters===
 
{{par begin}}
 
{{par begin}}
−
{{par | lhs, rhs | strings whose contents to swap}}
+
{{par|lhs, rhs|strings whose contents to swap}}
−
{{par end}}  
+
{{par end}}
  
 
===Return value===
 
===Return value===
Line 33: Line 35:
 
Constant.
 
Constant.
  
−
{{rrev |since=c++17|
+
{{rrev|since=c++17|
 
===Exceptions===
 
===Exceptions===
 
{{noexcept|noexcept(lhs.swap(rhs))}}
 
{{noexcept|noexcept(lhs.swap(rhs))}}
Line 40: Line 42:
 
===Example===
 
===Example===
 
{{example
 
{{example
−
| code=
+
|code=
−
#include <string>
+
 
#include <iostream>
 
#include <iostream>
 +
#include <string>
  
−
int main()  
+
int main()
 
{
 
{
 
     std::string a = "AAAA";
 
     std::string a = "AAAA";
Line 60: Line 62:
 
}
 
}
  
−
| output=
+
|output=
 
before swap
 
before swap
 
a: AAAA
 
a: AAAA
Line 76: Line 78:
 
===See also===
 
===See also===
 
{{dsc begin}}
 
{{dsc begin}}
−
{{dsc inc | cpp/string/basic_string/dsc swap}}
+
{{dsc inc|cpp/string/basic_string/dsc swap}}
 
{{dsc end}}
 
{{dsc end}}
  
 
{{langlinks|de|es|fr|it|ja|pt|ru|zh}}
 
{{langlinks|de|es|fr|it|ja|pt|ru|zh}}

Revision as of 10:09, 31 May 2023

 
C++
 
Strings library
 
std::basic_string
Member functions
(C++23)
Element access
(DR*)
(DR*)
(C++17)
Iterators
(C++11)
(C++11)
(C++11)
(C++11)
Capacity
(DR*)
Modifiers
(C++23)
(DR*)
(C++23)
(C++23)
(C++23)  
Search
Operations
(C++20)
(C++20)
(C++23)
Constants
Non-member functions
swap(std::basic_string)
(C++20)(C++20)
I/O
Comparison
(until C++20)(until C++20)(until C++20)(until C++20)(until C++20)(C++20)
Numeric conversions
(C++11)(C++11)(C++11)
(C++11)(C++11)
(C++11)(C++11)(C++11)
(C++11)
(C++11)
Literals
(C++14)
Helper classes
(C++11)
Deduction guides (C++17)

 
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).

Contents

Parameters

lhs, rhs - strings whose contents to swap

Return value

(none)

Complexity

Constant.

Exceptions

noexcept specification:  
noexcept(noexcept(lhs.swap(rhs)))
 (since C++17)

Example

Run this code
#include <iostream>
#include <string>
 
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) [edit]
Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/string/basic_string/swap2&oldid=152608"