shared_ptr <>到数组自定义删除器（使用make_shared）

Question

Is it possible to use make_shared and a custom deleter for an array that a shared_ptr<> points to (below is the way I tried doing it via the constructor, but I have no idea how that would work via using make_shared)?

int n = 5;
shared_ptr<int> a(new int[n], default_delete<int[]>());

What I would like to make it look like is something similar to this, but with allocating memory for an int array and also having a custom deleter. Is that possible?

int n = 5;
shared_ptr<int> a;
a = make_shared<int>();

Answer 1

Unfortunately there is no way to specify a custom deleter as of right now with std::make_shared , you could however, make a wrapper around make_shared if you want

( a little less efficient , but ¯\\_(ツ)_/¯)

template <typename Type, typename Deleter, typename... Args>
auto make_shared_deleter(Deleter&& deleter, Args&&... args) {
    auto u_ptr = std::make_unique<Type>(std::forward<Args>(args)...);
    auto with_deleter = std::shared_ptr<Type>{
        u_ptr.release(), std::forward<Deleter>(deleter)};
    return with_deleter;
}

And then use it like so

int main() {
    auto ptr = make_shared_deleter<int>(std::default_delete<int>(), 1);
    cout << *ptr << endl;
}

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If you just want to use a shared_ptr and have it point to an array, see shared_ptr to an array : should it be used? for more