difference in initialization constructor-CodePudding

I have a simple class with two objects in main(). Are there any differences in the initialization of the constructor ?

//#include <systemd/sd-bus.h>

#include <iostream>
#include <memory>

class Simple
{
    private:
        int a;
    public:
        Simple(int b) : a(b) { }
        void show() { std::cout << a; }
};


int main()
{
    Simple firstObj = Simple(5);
    firstObj.show();

    Simple secondObj(5);
    secondObj.show();

    return 0;
}

CodePudding user response：

Pre-C 17,

first one uses also copy(Pre-c 11)/move constructor (which might be elided) whereas second uses only Simple(int).
Since C 17,

both are equivalent.

CodePudding user response：

Simple firstObj = Simple(5); performs copy initialization, Simple secondObj(5); performs direct initialization, since C 17 they have the exact same effect: the object is initialized by the constructor Simple::Simple(int) directly.