Add Rml::Element::Matches function

[Paril]

This PR adds a simple function to mirror https://developer.mozilla.org/en-US/docs/Web/API/Element/matches in RmlUi; it was the only missing selector-related function in Element

[mikke89]

Thanks for the pull request! Looks good, I like it. And a documentation PR already as well, nice.

Could you add some unit tests as well? Please take a look at Selectors.cpp.

[Paril]

Thanks for the pull request! Looks good, I like it. And a documentation PR already as well, nice.

Could you add some unit tests as well? Please take a look at Selectors.cpp.

I added a quick harness and a few tests; I'm not great at unit testing because it tends to just be things that I need that I check for, heh.

[mikke89]

I think these tests look good. It tests the unique functionality of this function. The specific matching behavior is also shared with the other tests, so we don't need to go into full detail (although it wouldn't hurt either). Just a couple minor comments, and I'm ready to merge this.

[Paril]

I think these tests look good. It tests the unique functionality of this function. The specific matching behavior is also shared with the other tests, so we don't need to go into full detail (although it wouldn't hurt either). Just a couple minor comments, and I'm ready to merge this.

Fair enough! I also have :scope support just about ready for another PR. I'll address the comments above first.

[mikke89]

Nice, this looks good to me!

Thanks for the pull request, very much appreciated :)