On Tuesday, 31 January 2017 at 01:30:48 UTC, Walter Bright wrote:
By this information being knowable from the declaration, the compiler knows it too and can make use of it.
*Can* make use of it... But won't.Any code calling memcpy has to be in a @trusted wrapper, in which `return scope` is not checked. So adding `return scope` annotations to non-safe D binding is just like adding documentation. Which is on par with what C is doing, in the end.