Bug 12469 – opIndex does not work on pointers to structs

struct HasOpIndex { int opIndex(string s) { return 1; } } int main() { HasOpIndex* hoi = new HasOpIndex; return hoi["a"]; } ----------------- $ rdmd test.d test.d(5): Error: cannot implicitly convert expression ("a") of type string to ulong Failed: ["dmd", "-v", "-o-", "test.d", "-I."]

Indexing into pointers is a C feature that was carried over into D. Hence why the compiler expects you to pass a size_t index (ulong on x64). Use (*hoi)["a"] instead.