C++

Reference

<memory>

function template
<memory>

std::make_shared

template <class T, class... Args>  shared_ptr<T> make_shared (Args&&... args);
Make shared_ptr
Allocates and constructs an object of type T passing args to its constructor, and returns an object of type shared_ptr<T> that owns and stores a pointer to it (with a use count of 1).

This function uses ::new to allocate storage for the object. A similar function, allocate_shared, accepts an allocator as argument and uses it to allocate the storage.

Parameters

args
List of elements passed to T's constructor.
Args is a list of zero or more types.

Return Value

A shared_ptr object that owns and stores a pointer to a newly allocated object of type T.

Example

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
 
// make_shared example
#include <iostream>
#include <memory>

int main () {

  std::shared_ptr<int> foo = std::make_shared<int> (10);
  // same as:
  std::shared_ptr<int> foo2 (new int(10));

  auto bar = std::make_shared<int> (20);

  auto baz = std::make_shared<std::pair<int,int>> (30,40);

  std::cout << "*foo: " << *foo << '\n';
  std::cout << "*bar: " << *bar << '\n';
  std::cout << "*baz: " << baz->first << ' ' << baz->second << '\n';

  return 0;
}

Output:
*foo: 10
*bar: 20
*baz: 30 40


See also

allocate_shared
Allocate shared_ptr (function template)
shared_ptr::shared_ptr
Construct shared_ptr (public member function)
shared_ptr::operator=
shared_ptr assignment (public member function)