http://d.puremagic.com/issues/show_bug.cgi?id=2499
Summary: Template alias default value cannot be template instantiation Product: D Version: 2.019 Platform: PC OS/Version: Windows Status: NEW Keywords: rejects-valid Severity: normal Priority: P2 Component: DMD AssignedTo: [EMAIL PROTECTED] ReportedBy: [EMAIL PROTECTED] Simple case: void foo(T)() { } struct f(alias func=foo!(int)) { } void main() { f!() myf; } Error in 1.036: Error: foo!(int) is not a symbol Error in 2.019: testtemplatealias.d(5): Error: foo!(int) is used as a type testtemplatealias.d(11): template instance f!() does not match template declaration f(alias func = foo!(int)) testtemplatealias.d(11): Error: f!() is used as a type testtemplatealias.d(11): variable testtemplatealias.main.myf voids have no value Workaround is to alias the default parameter before using as the default parameter: alias foo!(int) defaultFoo; struct f(alias func=defaultFoo) { } --