C++, is it possible to call a constructor directly, without new?

Question

Can I call constructor explicitly, without using new, if I already have a memory for object?

class Object1{
    char *str;
public:
    Object1(c         


        

Answer 1

You can use the following template

template 
inline void InitClass(T &t, Args... args)
{
    t.~T();
    new (&t) T(args...);
}

usage:

struct A
{
   A() {}
   A(int i) : a(i) {}
   int a;
} my_value;

InitClass(my_value);
InitClass(my_value, 5);