Bug 19902 – hasElaborateCopyConstructor doesn't know about copy constructors

`hasElaborateCopyConstructor` in phobos (and also in druntime: core.internal.traits) needs to be updated to understand copy constructors. There may be some others that need tweaking too?

Indeed. Without it being updated, any existing code that's testing for whether it's okay to blit a type is broken when dealing with structs that have copy constructors (e.g. I expect that std.algorithm's swap is currently broken in such a fashion). I don't know if there's code that would break because it's really assuming postblit constructors from hasElaborateCopyConstructor rather than the inability to blit, but I expect that more code will be broken without updating the trait than with requiring a new one. Also, there's already been at least one post in D.Learn where someone was confused, because hasElaborateCopyConstructor wasn't true for types with copy constructors.

This is a very critical issue.

@edi33416 created dlang/druntime pull request #2709 "Fix Issue 19902 - hasElaborateCopyConstructor doesn't know about copy…" fixing this issue: - Fix Issue 19902 - hasElaborateCopyConstructor doesn't know about copy constructors https://github.com/dlang/druntime/pull/2709

@pbackus created dlang/druntime pull request #2911 "Fix issue 19902 - hasElaborateCopyConstructor doesn't know about copy…" fixing this issue: - Fix issue 19902 - hasElaborateCopyConstructor doesn't know about copy constructors https://github.com/dlang/druntime/pull/2911

dlang/druntime pull request #2911 "Fix issue 19902 - hasElaborateCopyConstructor doesn't know about copy…" was merged into stable: - 0c3fd57891f7ee6fa65b57bc2011f301017399e4 by Paul Backus: Fix issue 19902 - hasElaborateCopyConstructor doesn't know about copy constructors https://github.com/dlang/druntime/pull/2911