Bug 23970 – [REG2.097.0] Deprecation not emitted when selectively importing deprecated function

This isn't so bad because a deprecation is still emitted when the function is used. But still, it should probably be emitted on a selective import too. //////////////// a.d //////////////// deprecated int var; deprecated void fun() {} /////////////// test.d ////////////// // import a : var; // OK, deprecation import a : fun; // No deprecation? ///////////////////////////////////// Introduced in https://github.com/dlang/dmd/pull/12442

I think this behavior is fine. Note that `fun` may also have a non-deprecated overload, in which case you are selectively importing an overload set. In that case, it would be wrong to output a deprecation. In this case, checking all overloads for a non-deprecated one seems like an overkill. From that point of view, having an overload set of just one overload means that we don't have to output the deprecation. Of course, a special case can be added: for overload sets with just one overload check if it is deprecated, but this seems overkill to me; the deprecation is going to be issued at the call site any way.

That sounds fine to me. I just want to note that maybe deprecation should be a property that is tracked for overload sets; then, maintaining that property on the overload set, and checking if all of the functions in the overload set are deprecated, become a O(1) operation.

Yes, it could be implemented, however it will add cyclomatic complexity for no apparent benefit since the deprecation is issued on the call site anyway.