A RetroSearch Logo

Home - News ( United States | United Kingdom | Italy | Germany ) - Football scores

Search Query:

Showing content from https://cplusplus.com/reference/utility/make_pair/ below:

function template

<utility>

std::make_pair 
template <class T1, class T2>  pair<T1,T2> make_pair (T1 x, T2 y);
template <class T1, class T2>  pair<V1,V2> make_pair (T1&& x, T2&& y);  // see below for definition of V1 and V2

Construct pair object

Constructs a pair object with its first element set to x and its second element set to y.

The template types can be implicitly deduced from the arguments passed to make_pair.

pair objects can be constructed from other pair objects containing different types, if the respective types are implicitly convertible.

The behavior of this function template is the same as if defined as:


1
2
3
4
5
template <class T1,class T2>
  pair<T1,T2> make_pair (T1 x, T2 y)
  {
    return ( pair<T1,T2>(x,y) );
  }

The function returns:


1
pair<V1,V2>(std::forward<T1>(x),std::forward<T2>(y))

Where the types

V1

and

V2

are the

decay

equivalents of

T1

and

T2

, respectively (except for

reference_wrapper

types, for which the corresponding reference type is used instead).

If T1 and/or T2 are rvalue references, the objects are moved and x and/or y are left in an undefined but valid state.



Parameters
x, y
Values for the members first and second, respectively, of the pair object being constructed.

Return value A pair object whose elements first and second are set to x and y respectivelly.
The template parameters can be implicitly deduced.

Example 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
// make_pair example
#include <utility>      // std::pair
#include <iostream>     // std::cout

int main () {
  std::pair <int,int> foo;
  std::pair <int,int> bar;

  foo = std::make_pair (10,20);
  bar = std::make_pair (10.5,'A'); // ok: implicit conversion from pair<double,char>

  std::cout << "foo: " << foo.first << ", " << foo.second << '\n';
  std::cout << "bar: " << bar.first << ", " << bar.second << '\n';

  return 0;
}

Output:


Data races If either (or both) T1 or T2 is an rvalue reference type of a type supporting move semantics, its corresponding argument is modified.

Exception safety The function provides the same level of guarantees to each object as provided by the corresponding element constructor.

See also
pair::pair
Construct pair (public member function)

RetroSearch is an open source project built by @garambo | Open a GitHub Issue

Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo

HTML: 3.2 | Encoding: UTF-8 | Version: 0.7.4