std::unique_ptr (3) Linux Manual Page
std::unique_ptr<T,Deleter>::~unique_ptr – std::unique_ptr<T,Deleter>::~unique_ptr
Synopsis
~unique_ptr(); (since C++11)
If get() == nullptr there are no effects. Otherwise, the owned object is destroyed via get_deleter()(get()).
Requires that get_deleter()(get()) does not throw exceptions.
Notes
Although std::unique_ptr<T> with the default deleter may be constructed with incomplete_type T, the type T must be complete at the point of code where the destructor is called.
Example
The following program demonstrates usage of a custom deleter.
// Run this code
#include <iostream>
#include <memory>
int main()
{
auto deleter = [](int *ptr) {
std::cout << "[deleter called]\n";
delete ptr;
};
std::unique_ptr<int, decltype(deleter)> uniq(new int, deleter);
std::cout << (uniq ? "not empty\n" : "empty\n");
uniq.reset();
std::cout << (uniq ? "not empty\n" : "empty\n");
}
Output: