I have written a test class to but i'm failing to understanding whats happening!.
Is the Move/copy being elided? if so how could it be updated with the new value. i'm definitely missing something.
here is the test case(Please dont consider the usefulness)
#include<iostream>
struct Test
{
int a;
Test(){a = 10;std::cout<<"def\n";}
Test(int a){this->a = a;std::cout<<"unary\n";}
Test(const Test& a){this->a = a.a; std::cout<<"copy\n";}
Test(Test&& a){this->a = a.a; std::cout<<"Move\n";}
Test& operator=(const Test& a){this->a = a.a;std::cout<<"op=\n";}
Test& operator=(Test&& a){this->a = a.a;std::cout<<"Move=\n";}
void display(){std::cout << "Display ";}
};
Test gi(Test a)
{
std::cout<<a.a<<"&\n";
return a;
}
int main()
{
//Test a = 99;
//Test();
/*Line MST*/ Test b = Test(102);//gi(a);
std::cout<<b.a<<'\n';
return 0;
}
here line MST is what i dont understand. if i initialize it with a temporary Test object should it not call Move constructor(or atleast the copy)?
the output is :
unary
102
similar output with this line
Test b = gi(Test(103));
here Move/copy is not happening during call to gi()?
but this is as i expect
Test a = 99;
Test b = gi(a);
what am i missing here?