is(x = module) vs. __traits(isModule, x)

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On Wednesday, 7 October 2020 at 20:19:57 UTC, Paul Backus wrote:
> Couldn't you unconditionally lower <Node>.__isModule to 
> __traits(isModule, <Node>) regardless of what type of node it 
> is, and rely on the existing error messages for incorrect trait 
> arguments? You don't have to worry about shadowing "real" 
> properties, because anything that starts with "__" is a 
> reserved identifier.

struct Wrapper(alias sym)
{
     import std.format: format;

     template opDispatch(string name, Args...)
     //Not DRY, probably a better way to do this
     if (__traits(compiles, mixin(`__traits(%s, sym, 
Args)`.format(name))))
     {
         enum opDispatch = mixin(`__traits(%s, sym, 
Args)`.format(name));
     }
}

void main()
{
	import std.stdio;

     writeln(Wrapper!(std).isPackage);
}