October 10
I have a static opApply in a class and I need to iterate over all the members statically using foreach

	// Iterates over all members
	static int opApply(int delegate(cPiece) dg)
	{
		alias T = typeof(this);
		foreach (m; __traits(derivedMembers, T))
		{
			import std.traits : hasStaticMember;
			static if (hasStaticMember!(T, m))
			{
			    mixin("dg(X."~m~");");
					
			}
		}
		return 0;
	
	}


This is not a problem using foreach.


But when I use static foreach it fails!!!

Says that it cannot interpret X(the class that contains the static opApply).

the opApply is static, it does everything at compile time, so why can't the foreach be statically used?

The whole point of using opApply was so that I wouldn't have to write all that code each time and I could just iterate over class members when I need to.

October 10
On 10/10/2018 04:03 PM, James Japherson wrote:> Says that it cannot interpret X(the class that contains the static> opApply).
It's a bit hard to diagnose the problem you're getting using that function when we don't have the code that uses it. Or the context that's referenced with the foreach loop there. You might want to post a larger segment of code and the entire error message.

The error I'm seeing that might be related is: opApply is a static member of the type. So part of the function (after mixins) reads:

    dg(X.opApply);

This attempts to call X.opApply with no arguments and pass the result to dg. But X.opApply requires an argument.

You probably want to add a `is(typeof(mixin("X." ~ m)) == cPiece)` in there.