...eax, [<adress of u>]
        neg     eax                  ; because we subtracted in the wrong order
lable:  ret

...eax, ebx
label2:
	(ret)

The 2nd branch can be replaced with ret if opCmp is...

...movw	%ax, -10(%rsp)
	fistpl	-4(%rsp)
	fldcw	-10(%rsp)
	movl	-4(%rsp), %eax
	ret

...movw	%ax, -10(%rsp)
	fistpl	-4(%rsp)
	fldcw	-10(%rsp)
	movl	-4(%rsp), %eax
	ret

...RDX,RDI
        //    and    xchg RDX,R9 correctly
        ret;
    }
    }
}


ulong nobug(ulong a, ulong b, ulong...

...auto ret = new T[](numreads);
	
	size_t read = index;
	foreach(i;0..numreads) {
		ret[i...

...typeof(this) save()
    {
        auto ret = this;
        ret._input = _input.save;
        return ret;
    }
}
//----

This will split...

...replace those "ret = XXX" with straight up "return XXX". The last "return ret" should be...

...rhs[currentColumn] )
        ret = true;
      if (rhs[currentColumn] < lhs[currentColumn] )
	ret = false;
   }
   return ret;
}

Calling sort...

...dg.ptr);
        ret = (*dg)(nframes);
        writeln("3. end");
        return ret;
      };

   ...