Need equivalent of scoped select/rename helpers

[hadley]

Since across() doesn't help with this problem.

Maybe select() and rename() could gain a .transform argument that would be applied to the variable names?

[hadley]

Would be nice if df %>% rename_if("Count of (.*?) [Ff]emales", "\\1 count") could work (i.e. special case string inputs so that you could reuse regexp groups in the output).

[hadley]

Maybe rename_with() as a name?