[spacechild1]

> One never writes such expression in a serious code.

Oh please, because you know exactly which kind of code I write? I'm pretty sure that with glm::vec3 the compiler can optimize this just fine. Also, "vec" could really be anything, it is just a placeholder.

That being said, if you need to break up your statements, you can do so with operators:

    auto t = vec1 - vec2;
    t *= 0.5/0.3;
    t += vec3;
    t *= 0.3;

Personally, I find this much more readable. But hey, apparently there are people who really prefer free functions. I accept that.