std::unique_ptr<T,Deleter>::reset - cppreference.com (original) (raw)

Replaces the managed object.

1,2) Equivalent to auto old_ptr = get();
/* assigns “ptr” to the stored pointer */
if (old_ptr)
get_deleter()(old_ptr);.

If get_deleter()(old_ptr) throws an exception, the behavior is undefined.

1. This overload participates in overload resolution only if U is the same type as pointer, or all following conditions are satisfied:

• pointer is the same type as element_type*.
• U is a pointer type V* such that V(*)[] is convertible to element_type(*)[].

1. Equivalent to reset(pointer()).

[edit] Parameters

[edit] Notes

To replace the managed object while supplying a new deleter as well, move assignment operator may be used.

A test for self-reset, i.e. whether ptr points to an object already managed by *this, is not performed, except where provided as a compiler extension or as a debugging assert. Note that code such as p.reset(p.release()) does not involve self-reset, only code like p.reset(p.get()) does.

[edit] Example

#include #include   struct Foo // object to manage { Foo() { std::cout << "Foo...\n"; } Foo() { std::cout << "Foo...\n"; } };   struct D // deleter { void operator() (Foo* p) { std::cout << "Calling delete for Foo object... \n"; delete p; } };   int main() { std::cout << "Creating new Foo...\n"; std::unique_ptr<Foo, D> up(new Foo(), D()); // up owns the Foo pointer (deleter D)   std::cout << "Replace owned Foo with a new Foo...\n"; up.reset(new Foo()); // calls deleter for the old one   std::cout << "Release and delete the owned Foo...\n"; up.reset(nullptr);
}

Output:

Creating new Foo... Foo... Replace owned Foo with a new Foo... Foo... Calling delete for Foo object... ~Foo... Release and delete the owned Foo... Calling delete for Foo object... ~Foo...

[edit] Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

[edit] See also

| | returns a pointer to the managed object and releases the ownership (public member function) [edit] | | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |