https://issues.dlang.org/show_bug.cgi?id=21705
--- Comment #1 from Paul Backus <[email protected]> --- Another example: --- import std.typecons; struct S { int n; bool opEquals(S rhs) { return n == rhs.n; } } void main() { Nullable!S example1 = S(1), example2 = S(1); assert(example1 == example2); } --- Produces the following error message with DMD 2.095.1: --- /usr/include/dmd/phobos/std/typecons.d(2726): Error: mutable method `bug.S.opEquals` is not callable using a `const` object bug.d(6): Consider adding `const` or `inout` here bug.d(12): Error: template instance `std.typecons.Nullable!(S).Nullable.opEquals!()` error instantiating --- --
