Bug 16584 – Local import ineffective for mixin templates

Consider the following code: // func.d module func; public uint toNumber(string str) { return str[0]; } // mixins.d module mixins; import func; mixin template bla(string number) { uint globalBla = toNumber(number); } // app.d module app; import mixins; public void main() { mixin bla!"aaa"; } When compiled, the following compilation error is shown: src\mixins.d(6,19): Error: undefined identifier 'toNumber' src\app.d(6,2): Error: mixin app.main.bla!"aaa" error instantiating I expected the import of module 'func' to be only needed at the site of the mixin declaration, not where the mixin is used. Publicly importing module 'func' in mixins.d works around the problem, as does importing module 'func' in app.d.

From the documentation: "Unlike a template instantiation, a template mixin's body is evaluated within the scope where the mixin appears, not where the template declaration is defined." So this is actually by design. Closed the issue.

For the record: the best solution is to import the needed modules within the mixin: mixin template bla(string number) { import func; uint globalBla = toNumber(number); } This keeps within the scope of the mixin body.