Expand ZeroFrom to cover cases where attrs can borrow #3770
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5 tasks
sffc
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Aug 10, 2023
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This adds
zerofrom(may_borrow), which allows derivingZeroFromon generic types which have parameters we care about borrowing.I'm not happy about the terminology in ZF, we have a couple things talking about the same thing:
zero_from, and the type parameter ofZeroFrom'zf_inner, which is the lifetime of the "C type"lifetime_ty, which is the C type version of the field type. usually the type with'zf_innerreplacing its main lifetimeI'd like to come up with a nice name for these things we can make consistent. I try to document this a bit better here though.
I'm doing this in an attempt to start using generics in datetime symbols code more; I have #3767 open but I want to try and clean up the rest.
If this approach works I plan to do something similar in Yoke.
may_borrowcan't be applied directly to type parameters due to rust-lang/rust#114393. This code is future-proof for whenever that upstream bug is fixed.Part of #3771