std::make_shared
From cppreference.com
< cpp | memory | shared ptr
| Defined in header <memory>
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| template< class T, class... Args > shared_ptr<T> make_shared( Args... args ); |
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Constructs an object of type T and wraps it in a std::shared_ptr using args as the parameter list for the constructor of T.
Contents |
[edit] Parameters
| args | - | list of arguments with which an instance of T will be constructed. |
[edit] Return value
std::shared_ptr of an instance of type T.
[edit] Complexity
Constant time given the T constructor also have a constant complexity.
[edit] Notes
This function allocates memory for the T object and for the shared_ptr's control block with a single memory allocation. In contrast, the declaration std::shared_ptr<T> p(new T(Args...)) performs two memory allocations, which may incur unnecessary overhead.
[edit] Example
#include <iostream> #include <memory> void foo(std::shared_ptr<int> i) { (*i)++; } int main() { auto sp = std::make_shared<int>(10); foo(sp); std::cout << *sp << std::endl; }
Output:
11
[edit] See also
| creates a shared pointer that manages a new object allocated using an allocator (function template) | |
