import std.traits, std.stdio;

void times(F)(uint n, F func)
    if (isSomeFunction!F)
{
    immutable ar = arity!func;

    foreach (uint i; 0 .. n) {
        static if (ar == 0) {
            func();
        } else static if (ar == 1) {
            func(i);
        } else {
            static assert(false, "invalid callable");
        }
    }
}

void main() {
    10.times((uint i) => writeln("hello #", i));
}