Add isrem type checking function

[sgarrity]

We've got type checking functions for ispixel, ispercentage, isem. Let's add one for rem units.

[seven-phases-max]

Use isunit instead. (Technically a potential amount of possible CSS units is infinite so...). Also see #1549.

[sgarrity]

I since discovered isunit and it worked for my needs. Are pixel, percentage, and em special cases just because they are the most common?

[seven-phases-max]

Are pixel , percentage , and em special cases just because they are the most common?

Well, I think it would be quite fair to guess that "they were most common for one who added them (several years ago)". By now it's only about backward-compatibility to keep them in Less.

[sgarrity]

Well, I think it would be quite fair to guess that "they were most common for one who added them (several years ago)". By now it's only about backward-compatibility to keep them in Less.

Fair enough - maybe the should be noted as such with a code-comment or in the docs, or deprecated?

[seven-phases-max]

maybe the should be noted as such with a code-comment or in the docs, or deprecated?

They are not planned for removing (yet at least) so no "deprecated" for them.
As for for any notes in the documentation - well, I don't think it's worth... documenting "design rationale", "history", "future plans" etc. etc. for every single Less feature/function would be... well, you can guess...
In other words, for not-well-thought features/functions: "what's in is in, but do not add more of those".

[sgarrity]

Fair enough. Thanks for the consideration and reply.