Returning a struct in a void func()

Question

I'm trying to compile my code from the old MS-DOS days and this doesn't seem to work with GCC:

    typedef struct { int x,y,z; } vector;

    inline void vect_add(vector& c,vector a, vector b)
    {
        c.x=a.x+b.x;
        c.y=a.y+b.y;
        c.z=a.z+b.z;
    }

Basically I'm trying to return a struct which is later used as vector.x etc instead of rewriting it as a pointer to struct and rewriting all as vector->x etc

see (vector& c,

C does not have the C++ style reference syntax which you are trying to use. — Eugene Sh.
– Eugene Sh., Commented Oct 25, 2021 at 13:59
C doesn't have references. You need to emulate it using pointers. — Some programmer dude
– Some programmer dude, Commented Oct 25, 2021 at 14:00
As mentioned by @EugeneSh. the syntax you try to use is C++. Are you sure that the project you're trying to build is not a C++ project? — Some programmer dude
– Some programmer dude, Commented Oct 25, 2021 at 14:00
I assume this used to work? So you might need to make sure GCC correctly runs in C++ mode, not in C mode. — PMF
– PMF, Commented Oct 25, 2021 at 14:00
What's the name of the source code file? Are you using g++ or gcc? — Ted Lyngmo
– Ted Lyngmo, Commented Oct 25, 2021 at 14:01

chux · Accepted Answer · 2021-10-25 14:47:31Z

1

That is possibly valid C++, but it's not valid C.

In C, you need to use a pointer, a global var, or actually return a struct.

typedef struct { int x, y, z; } vector;

inline void vect_add(vector* c, vector a, vector b)
{
    c->x = a.x + b.x;
    c->y = a.y + b.y;
    c->z = a.z + b.z;
}

vect_add(&c, a, b);

edited Oct 25, 2021 at 14:47

chux

158k17 gold badges160 silver badges311 bronze badges

answered Oct 25, 2021 at 14:07

ikegami

391k17 gold badges291 silver badges555 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Returning a struct in a void func()

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related