Usage of both scalar and array in smart pointer

Question

How can I use both scalar and array in smart pointer?

The old way of using new and delete pointer:

int *p;

if (useScalar) {
    p = new int;
} else {
    p = new int[10];
}

if (useScalar) {
    delete p;
} else {
    delete[] p;
}

In smart pointer, I have to use 2 pointers for each scalar and array pointer:

std::unique_ptr<int> p1(new int);
std::unique_ptr<int[]> p2(new int[10]);

How can I decrease to use only 1 smart pointer?

Answer 1

If you use a custom deleter, you can use the same type for either pointer.

std::unique_ptr<int, void(*)(int*)> p = {nullptr, [](int*){}};
if (useScalar) {
    p = {
        new int,
        [](int* p){delete p;}
    };
} else {
    p = {
        new int[10],
        [](int* p){delete[] p;},
    };
}