Replace NonCopyable usage with NoPod

[flaper87]

cc #10834

[flaper87]

@huonw r?

[huonw]

Isn't this testing replace, not NonCopyable?

Maybe change the test to something like Some(~"foo").

[flaper87]

erm, good catch!

[pnkfelix]

Is it just me, or is "NoPod" less readable than "NonCopyable" ? :(

(I guess I did not mind it or notice so much when it was buried in the rest of PR #11768 but here it seems to bother me.)

I would have been fine if NonCopyable had stayed and we just changed its definition to be based upon having a NoPod field rather than a non_copyable attribute...

[flaper87]

@pnkfelix you mean just having a NonCopyable struct with a NoPod field and without the destructor?

[flaper87]

Also, FWIW, it doesn't bothers me much. TBH!

[pnkfelix]

@flaper87 yes, a field and deleting the destructor is what I meant. (In my earlier comment I had forgotten the current implementation strategy for NonCopyable (a destructor plus a no-drop-flag attribute.)

Anyway I was just voicing my personal taste, I do not care enough about the readability issue here to try to block your change. After all my own taste might change in time.

[flaper87]

@alexcrichton r?