make_shared

make_shared.cxx

#include <iostream>
#include <memory>
#include <stdexcept>

template <class T, class... T_params>
auto make_shared(T_params&&... params) -> std::shared_ptr<T>
{ return std::shared_ptr<T>(new T(params...)); }

class A
{
    friend class B;
    template <class T, class... T_params> friend auto make_shared(T_params&&... params) -> std::shared_ptr<T>;
    
    int x = 0;
    
    static auto operator new(unsigned long s) -> void* { std::cerr << "new " << s << "\n"; return std::malloc(s); }
    A() { std::cerr << "ctor\n"; }
    
public:
    static auto operator delete(void* p) -> void { std::cerr << "delete " << p << "\n"; return std::free(p); }
    ~A() { std::cerr << "dtor\n"; }
};

class B: public A
{
    template <class T, class... T_params> friend auto make_shared(T_params&&... params) -> std::shared_ptr<T>;
    int y = 0;
};

auto main() -> int
{
    //auto a1 = A();
    auto a2 = make_shared<A>();
    //auto b1 = B();
    auto b2 = make_shared<B>();
}

Start

new 4
ctor
new 8
ctor
dtor
delete 0x131a7f0
dtor
delete 0x131a950

0

Finish