[mk12]

The problem is not that + calls a function. The problem is that + could call one of many different functions, i.e. it is overloaded. Zig does not allow overloading plus() based on the argument types. When you see plus(), you know there is exactly one function named “plus” in scope and it calls that.

[gpderetta]

operator + is overloaded even in plain C: it will generate different instructions for pointers, floats, integers, _Complex, _Atomic and the quasi standard __float128. Sometimes it will even generate function calls.

I suspect zig might be similar.

[kps]

Not if `plus` is a pointer. Then `plus()` is a conditional branch where the condition can be arbitrarily far away in space (dynamically scoped) and time. That's why I think invisible indirection is a mistake. (C used to require `(*plus)()`.)

[gpderetta]

or 'plus' could be a macro...