I can do this in c++/g++:
struct vec3 {
union {
struct {
float x, y, z;
};
float xyz[3];
};
};
Then,
vec3 v;
assert(&v.xyz[0] == &v.x);
assert(&v.xyz[1] == &v.y);
assert(&v.xyz[2] == &v.z);
will work.
How does one do this in c with gcc? I have
typedef struct {
union {
struct {
float x, y, z;
};
float xyz[3];
};
} Vector3;
But I get errors all around, specifically
line 5: warning: declaration does not declare anything
line 7: warning: declaration does not declare anything
according to http://gcc.gnu.org/onlinedocs/gcc/Unnamed-Fields.html#Unnamed-Fields
-fms-extensions
will enable the feature you (and I) want.