3512 – dchar iteration over string in CTFE fails

Code:
 string s = "ohai";
 foreach (int i, dchar c; s)
 {}
Error:
Error: cannot evaluate _aApplycd2(s,int delegate(ref int __applyArg0, ref dchar __applyArg1)
{
dchar c2 = __applyArg1;
int i = __applyArg0;
if (cast(uint)c == cast(uint)c2)
__result = i;
return 2;
return 0;
}
) at compile time
foreach(dchar c; s) also fails similarly.

This does work for me using dmd 2.037 and later but not using dmd 1.055 on Mac OS X.

I'm seeing a similar error. dmd 2.050 on OS X.
Code:
 import std.string;
 void main()
 {
 mixin("int " ~ tolower("A") ~ ";");
 }
Error:
/Users/drothlis/dmd2/osx/bin/../../src/phobos/std/string.d(792): Error: _aApplycd2 cannot be interpreted at compile time, because it has no available source code
minimal.d(5): Error: cannot evaluate tolower("A") at compile time

(In reply to comment #2)
Whereas the original code posted by Bill Baxter compiles successfully.

(In reply to comment #3)
Please ignore comment #3 :)

This still fails, and will most likely be fixed by issue 6268.

*** Issue 6268 has been marked as a duplicate of this issue. ***

https://github.com/D-Programming-Language/dmd/commit/9318dc44c3e9aa75907966b9fd122c0cc6700891
https://github.com/D-Programming-Language/dmd/commit/571661646ca420aa4c3fb348e86e35ed8faae624