Lift $dst outside the closure in write! #12240
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| other: &'a str, | ||
| } | ||
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| fn uh_oh(foo: Foo) { |
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Probably don't want it called uh_oh any more now that you've fixed it so it works!
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LGTM (replacing the macro fixed the problem in rust-http). |
If you were writing to something along the lines of `self.foo` then with the new closure rules it meant that you were borrowing `self` for the entirety of the closure, meaning that you couldn't format other fields of `self` at the same time as writing to a buffer contained in `self`. By lifting the borrow outside of the closure the borrow checker can better understand that you're only borrowing one of the fields at a time. This had to use type ascription as well in order to preserve trait object coercions.
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If you were writing to something along the lines of
self.foothen with the newclosure rules it meant that you were borrowing
selffor the entirety of theclosure, meaning that you couldn't format other fields of
selfat the sametime as writing to a buffer contained in
self.By lifting the borrow outside of the closure the borrow checker can better
understand that you're only borrowing one of the fields at a time. This had to
use type ascription as well in order to preserve trait object coercions.