How to pass deleter to make_shared?

Question

Since C++11, because of several reasons, developers tend to use smart pointer classes for dynamic lifetime objects. And with those new smart pointer classes, standards, even

Answer 1

If you use a custom deleter you can't use make_unique or make_shared functions when you create a smart pointer objects . Since we need to provide our custom deleter these functions do not support that .

Don't use make_unique or make_shared if you need a custom deleter or adopting a raw pointer from elsewhere.

The idea is if you need a specialized way to delete your object you probably need a specialized way to create them too .

Let say we a class Test

#include     
using namespace std;    
class Test
{
private : 
    int data; 
    public : 
    Test() :data{0}
    {
        cout << "Test constructor (" << data << ")" << endl;
    }
    Test(int d) : data{ d }
    {
        cout << "Test constructor (" << data << ")" << endl; 
    }
    int get_data() const { return data; }
    ~Test()
    { 
        cout << "Test Destructor (" << data << ')' << endl; 
    }
};

// main function. 
int main()
{
   // It's fine if you use  make_shared and custom deleter like this
   std::shared_ptr ptr(new Test{1000},
            [](Test *ptr)
            {
                cout << "some Code that you want to execute "; 
                delete ptr;
            });
         return 0;
}

But if you use make_shared function you will get a compiler error

std::shared_ptr ptr = make_shared(1000,
            [](Test *ptr){
               cout << "some Code that you want to execute "; 
               delete ptr;
            });

Basically make_shared function is a wrapper for new and delete and if you want a custom deleter you have to provide you own new and delete