Bug 11364 – Variant fails to compile with const(TypeInfo).

Not entirely sure the cause of this. The following code fails to compile: import std.variant; void main() { const(TypeInfo) ti = typeid(TypeInfo); Variant v = ti; } Output: rdmd test.d /Users/kapps/dev/dmd/phobos/std/variant.d(333): Error: mutable method object.TypeInfo.opCmp is not callable using a const object /Users/kapps/dev/dmd/phobos/std/variant.d(377): Error: mutable method object.TypeInfo.opCmp is not callable using a const object /Users/kapps/dev/dmd/phobos/std/variant.d(600): Error: template instance std.variant.VariantN!(32LU).VariantN.handler!(const(TypeInfo)) error instantiating /Users/kapps/dev/dmd/phobos/std/variant.d(550): instantiated from here: opAssign!(const(TypeInfo)) test.d(16): instantiated from here: __ctor!(const(TypeInfo)) /Users/kapps/dev/dmd/phobos/std/variant.d(550): Error: template instance std.variant.VariantN!(32LU).VariantN.opAssign!(const(TypeInfo)) error instantiating test.d(16): instantiated from here: __ctor!(const(TypeInfo)) test.d(16): Error: template instance std.variant.VariantN!(32LU).VariantN.__ctor!(const(TypeInfo)) error instantiating Seems like it tries to call opCmp with the const instance even if opCmp is not const. Yet the following sample works: import std.variant; class Foo { override int opCmp(Object o) { return 0; } override bool opEquals(Object o) { return 0; } } void main() { const(Foo) inst = new Foo(); Variant v = inst; } Not entirely sure why it doesn't work with TypeInfo then which has the exact same opCmp and opEquals signatures.

This was fixed by the fix for 12157.