https://issues.dlang.org/show_bug.cgi?id=14251
--- Comment #21 from Martin Nowak <c...@dawg.eu> --- (In reply to Andrei Alexandrescu from comment #19) > > Just look at core.sync, none of the methods can be implemented const or > > pure, still they get called from const/pure code. > > That's not a problem, the runtime is expected to contain nonportable code. I'd say the real attribute problem is not the automatic mutex generated for `synchronized (instance)`, b/c we can control how that behaves. But b/c it's possible to assign an arbitrary Object.Monitor implementation, people can run very different Mutex implementations. As usual there is no deprecation path for adding attributes to an interface/base-class, and the last time we tried to make Object.Monitor nothrow, we broke valid use cases in vibe.d that we're using async/event-based mutexes. Now this bug report is about the effect that _d_monitorenter/exit do call any Mutex implementation w/o checking for attributes. We had so many problems w/ attributes and old C compiler-runtime APIs, and it always boils down to this: Forcing everyone to use the same attributes is too limiting/breaks code, let's replace the old C API w/ templated library code. --