In Bringhurst's Elements* he directs us to use upright parentheses, brackets, and braces even if the context is italic.**
Not like (for example) this
but (rather) like this.
I'm curious: has anyone released a font in which the parentheses etc. slots in the italic font house upright glyphs?
* section 5.3.2 in my version (2.5)
** he does mention a special case (brackets that are part of a title) in which sloped brackets would be appropriate.