const can be cast away, auto can have some really nasty behavior, constexpr doesn't have to do anything, inline can be ignored, [[nodiscard]] can be discarded, exceptions can be thrown in noexcept functions, etc. Almost everything in C++ can be bypassed in one way or another.

D can cast away const, but not in @safe code. Though we are considering revising this so it can only be done in @system code.