[lex.phases],[forward.list.ops],[list.ops],[alg.unique] Hyphenate non-empty

[eisenwave]

No description provided.

[jensmaurer]

Hm... The wiki says we want to use "nonempty" for sets that are not empty:

https://github.com/cplusplus/draft/wiki/Specification-Style-Guidelines#hyphens-nonx-vs-non-x

(We don't have empty classes anymore, I think; the term is gone.)

It feels to me that a range that has no elements would be an "empty set", and thus "nonempty range" and "nonempty list" would be correct.

@tkoeppe , @zygoloid (as the author of the hyphenation rule): What do you think?

[eisenwave]

Hm... The wiki says we want to use "nonempty" for sets that are not empty:

I haven't noticed that rule when making my edit. It's surprising to me, because there are 18 uses of non-empty in the standard, and only 5 uses of nonempty, so I thought of it as an obvious inconsistency that can be fixed. You can even find two occurrences of non-empty set.

Empty is also a C++ term for strings at least, defined in [byte.strings], so doesn't it arguably fall under the first bullet in the wiki? At least it should for the change in [lex.phases] I've made.

The wiki also mentions nonempty as an example of a well-established non-hyphenated form. However, Google Trends suggests that non-empty is significantly more common, and I can't find any authoritative source that recommends nonempty. Overall, non-empty is more popular in the C++ standard and elsewhere.

Maybe the wiki should be updated, since its recommendation doesn't match common practice in the standard, or common practice elsewhere.

[JohelEGP]

#440 was reopened for this.

[lorihughes]

I was asked to chime in on this thread. Chicago Manual of Style omits the hyphen for prefixes most of the time. (We still include the hyphen when the characters are repeated, e.g., non-negative, or when necessary for clarity.) I double-checked several other popular style guides for their take: Butcher's Copy-Editing, New Oxford Style Manual, AP Stylebook, NYT Manual of Style and Usage, Dreyer's English. All agree that the hyphen should be omitted for nonempty.

[jensmaurer]

@lorihughes , thanks for your input here!

Side note: Hyphenation seems to be one of areas where US and British English sometimes differ, and Germans usually get exposed to British English at school. Also, technical texts possibly prefer hyphenation in some cases for visual clarity.

For me, it's "nonempty", and we should fix the offenders in the wording.

[lorihughes]

@lorihughes , thanks for your input here!

Side note: Hyphenation seems to be one of areas where US and British English sometimes differ, and Germans usually get exposed to British English at school. Also, technical texts possibly prefer hyphenation in some cases for visual clarity.

For me, it's "nonempty", and we should fix the offenders in the wording.

You're welcome!
Re the US/UK difference, that's why I consulted Oxford and Butcher's; those are both UK sources.

[tkoeppe]

Editorial meeting February 2025: Jens's representation in #6487 (review) of our wiki rule is on point. There are different contexts, and all the proposed changes concern the natural language meaning of "nonempty", which both our wiki rule and the style guide that @lorihughes cited say should use the unhyphenated form. The status quo (and our rule) seem to be good as is.