If you don't recall or know the name of the reference primitive (like, uh, I did earlier), searching on https://doc.rust-lang.org/std/ for "&", "&m", "&mu", and "&mut" should show the result "reference (primitive)" as the first result.
Likewise for [] and [;] for slices and arrays, and () and (,) and (,,) and etc. for tuples. And probably others.
If you don't recall or know the name of the reference primitive (like, uh, I did earlier), searching on https://doc.rust-lang.org/std/ for "&", "&m", "&mu", and "&mut" should show the result "reference (primitive)" as the first result.
Likewise for
[]and[;]for slices and arrays, and()and(,)and(,,)and etc. for tuples. And probably others.