Re: Range Construction Pattern

[Nordlöw]

My try so far:

import std.traits: isCallable, ReturnType, arity, 
ParameterTypeTuple;

enum arityMin0(alias fun) = __traits(compiles, fun()); // new 
syntax in 2.064

auto repeat(alias fun)(size_t n) if (isCallable!fun &&
                                     arityMin0!fun &&
                                     !is(ReturnType!fun == void))
{
    import std.range: iota, map;
    return n.iota.map!(n => fun);
}