[special] multiple concepts conflated in same paragraph

[zygoloid]

From Gaby:

Paragraph 12.4/5 defines two unrelated concepts:

1. a defaulted destructor that is defined as deleted;
2. the notion of trivial destructors

They should have their own paragraphs.

The same applies in other places in clause 12: see, for instance, 12.1/4, which specifies

1. what a defaulted constructor is
2. when a default constructor is implicitly declared and how it behaves
3. when a defaulted default constructor is deleted
4. when a defaulted default constructor is trivial

I think at least (3) and (4) should be in their own paragraphs. I have no particular opinion about whether (1) and (2) should be split up, but my inclination is to keep them together since the fact that you implicitly get a default constructor in some cases is fairly fundamental to the notion of a default constructor.

12.8 paragraphs 7-12 are a bit better (the 'deleted' and 'trivial' determination are already in their own paragraphs), but paragraph 11 is a bit confused: its opening sentence is about implicitly-declared constructors ("...is an inline public member..."), but the rest of the paragraph is about implicitly deleting defaulted constructors, which happens for non-implicitly-declared constructors too. The opening sentence of paragraph 11 would fit much better in, say, paragraph 7.

[jensmaurer]

12.4p5 is fixed already.
I've split up (3) and (4) in 12.1p4.
The first sentence of 12.8p11 is not moved earlier, because the concept of an implicitly-declared move constructor is introduced as late as p9. p11 is the first place where we talk about both copy and move constructors. We could have a separate paragraph for the first sentence of p11, but that gets us a questionable paragraph with a single sentence. In short, no changes to 12.8p11.