Implement additional formatting traits for [T]

[abonander]

Bringing rust-lang/rust#33127 back from the dead because I came across a desire for this feature today.

However, I would like to extend this proposal to include all the following traits and implement them for<T> [T] where T: <trait> (and presumably Vec<T> as well):

• Binary
• LowerExp
• UpperExp
• LowerHex
• UpperHex
• Octal
• Pointer

Finally, I would like to echo @retep998's proposal to just copy the Debug impl and use the above traits to format the elements. It fits considering that the main use for these formatting styles would be in debug or logging output anyway.

It may also be desirable to extend these impls to other collections types as well, using their Debug impls as a basis.

[golddranks]

I would love to see this happen.

[SimonSapin]

This was rejected in rust-lang/rust#44751. I proposed something different (based on Debug) in #2226.

[abonander]

Gonna close this since #2226 covers the original use-case I had in mind, and can be extended to the other formatting traits if necessary.