Does return statement copy values

Question

I am wondering about this because of scope issues. For example, consider the code

typedef struct {
    int x1;/*top*/
    int x2;/*bottom*/
    int id;
} sub         


        

Answer 1

In your case , it will return a copy

If your code was

subline_t& subline(int, int)

then it would return a reference, which would yield in undefined behaviour.