Bug 2848 – static if (is(type)) + alias fails to compile

This simple test fails to compile: static if (!is(typeof(no_type))) alias char[] no_type; no_type x; In all D compilers available, tested in GDC, DMD 1.043, DMD 2.027 and LDC r1197 (so it seems like a front-end issue). The error is: t.d:3: Error: identifier 'no_type' is not defined t.d:3: Error: no_type is used as a type t.d:3: variable t.x voids have no value This test doesn't compile either: static if (!is(typeof(no_type))) { alias char[] no_type; no_type y; } Error: t.d(3): Error: identifier 'no_type' is not defined t.d(3): Error: no_type is used as a type t.d(3): variable t.x voids have no value

BTW, using static if (is(typeof(no_type))) doesn't work either.

It seems to happen for array, int and float aliasee, but not for Object or struct types... This workaround works: alias char[] String; static if (!is(no_type)) { alias String no_type; no_type y; } no_type x; It seems not to fail when aliassed to user-defined types (classes, structs, enums, aliases, typedefs), but for primitive types and arrays it fails. typedef have the same problem.

Workaround: ---- alias char[] String; static if (!is(no_type)) alias String no_type; no_type x; ---- It seems to fail when the aliased type is a primitive type or array (static, dynamic or associative). It doesn't fail if it's a class, struct, enum, typedef or aliased type.

Works in DMD 1.062, I don't know when it got fixed. I guess it will work in DMD 2.0xx, but I don't have one installed to test. If somebody wants to try it, this bug can be closed (maybe Don who seems to bisect a lot and has an environment to do that easily wants to bisect DMD to see when it got fixed and add the proper changelog entry ;).

(In reply to comment #4) > Works in DMD 1.062, I don't know when it got fixed. I guess it will work in DMD > 2.0xx, but I don't have one installed to test. > > If somebody wants to try it, this bug can be closed (maybe Don who seems to > bisect a lot and has an environment to do that easily wants to bisect DMD to > see when it got fixed and add the proper changelog entry ;). No probs. Fixed DMD 1.050.

Thanks!(In reply to comment #5) > (In reply to comment #4) > > Works in DMD 1.062, I don't know when it got fixed. I guess it will work in DMD > > 2.0xx, but I don't have one installed to test. > > > > If somebody wants to try it, this bug can be closed (maybe Don who seems to > > bisect a lot and has an environment to do that easily wants to bisect DMD to > > see when it got fixed and add the proper changelog entry ;). > No probs. > Fixed DMD 1.050. Thanks =)