[CamouflagedKiwi]

requires is also new (not sure exactly when that appeared, it's after the last time I wrote C++ in anger) although I think it's fairly clear what it means. I can only guess at the other two.

Not familiar with Zig but AFAICT `inline for` is about instructing the compiler to unroll the loop, whereas `template for` means it can be evaluated at compile time and each loop iteration can have a different type for the iteration variable. It's a bit crazy but necessary for reflection to work usefully in the way the language sets it up.

[ginko]

Zig's inline for is also evaluated at comptime:

https://ziglang.org/documentation/master/#inline-for

[samatman]

Well yes, but the _effect_ is to unroll the loop for runtime, if the inline-for survives that long.

A for loop executed during comptime is just

    const stuff = comptime stuff: {
       for (0...8) |i| {
         // etc, build up some stuff
       }
       break :stuff some_stuff;
    };

The difference is that a comptime block won't leave behind runnable 'residue', only whatever data is constructed for later. An inline for might not leave behind an unrolled loop either, but it can.

[NooneAtAll3]

requires is concept, one of big-C-words of ++20