Bug 19541 – Confusing error message about missing opEquals for AA key

struct S { bool opEquals(ref const(S) that) const { here_is_a_compilation_error; } } struct T { string[S] aa; // <-- Compilation error } void main() { } Error: AA key type `S` does not have `bool opEquals(ref const S) const` The message is confusing because the AA key type S satisfies what it says. Apparently, the problem is actually with a compilation error inside that function but the user is fooled by the message and is now looking for unnecessary workarounds instead of fixing the compilation error. Ali

Compiling this example with the latest git master, I get: test.d(8): Error: AA key type `S` should have `extern (D) size_t toHash() const nothrow @safe` if `opEquals` defined Fine, I added the toHash myself: struct S { bool opEquals(ref const(S) that) const { here_is_a_compilation_error; } size_t toHash() const { return 1; } } struct T { string[S] aa; // <-- Compilation error } void main(){ } But now I get: test.d(3): Error: undefined identifier `here_is_a_compilation_error` This seems to have been fixed.