rust/src/test/ui/variance/variance-use-invariant-struct-1.nll.stderr

error: lifetime may not live long enough
  --> $DIR/variance-use-invariant-struct-1.rs:12:5
   |
LL | fn foo<'min,'max>(v: SomeStruct<&'max ()>)
   |        ---- ---- lifetime `'max` defined here
   |        |
   |        lifetime `'min` defined here
...
LL |     v
   |     ^ function was supposed to return data with lifetime `'max` but it is returning data with lifetime `'min`
   |
   = help: consider adding the following bound: `'min: 'max`
   = note: requirement occurs because of the type SomeStruct<&()>, which makes the generic argument &() invariant
   = note: the struct SomeStruct<T> is invariant over the parameter T
   = help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance

error: lifetime may not live long enough
  --> $DIR/variance-use-invariant-struct-1.rs:19:5
   |
LL | fn bar<'min,'max>(v: SomeStruct<&'min ()>)
   |        ---- ---- lifetime `'max` defined here
   |        |
   |        lifetime `'min` defined here
...
LL |     v
   |     ^ function was supposed to return data with lifetime `'max` but it is returning data with lifetime `'min`
   |
   = help: consider adding the following bound: `'min: 'max`
   = note: requirement occurs because of the type SomeStruct<&()>, which makes the generic argument &() invariant
   = note: the struct SomeStruct<T> is invariant over the parameter T
   = help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance

error: aborting due to 2 previous errors
Change compare mode to use -Zborrowck=mir 2019-01-27 05:03:21 -06:00			`error: lifetime may not live long enough`
			`--> $DIR/variance-use-invariant-struct-1.rs:12:5`
			`\|`
			`LL \| fn foo<'min,'max>(v: SomeStruct<&'max ()>)`
			\| ---- ---- lifetime `'max` defined here
			`\| \|`
			\| lifetime `'min` defined here
			`...`
			`LL \| v`
Ensure that early-bound function lifetimes are always 'local' During borrowchecking, we treat any free (early-bound) regions on the 'defining type' as `RegionClassification::External`. According to the doc comments, we should only have 'external' regions when checking a closure/generator. However, a plain function can also have some if its regions be considered 'early bound' - this occurs when the region is constrained by an argument, appears in a `where` clause, or in an opaque type. This was causing us to incorrectly mark these regions as 'external', which caused some diagnostic code to act as if we were referring to a 'parent' region from inside a closure. This PR marks all instantiated region variables as 'local' when we're borrow-checking something other than a closure/generator/inline-const. 2021-12-31 15:55:34 -06:00			\| ^ function was supposed to return data with lifetime `'max` but it is returning data with lifetime `'min`
update tests 2019-10-27 09:39:14 -05:00			`\|`
			= help: consider adding the following bound: `'min: 'max`
Refactor variance diagnostics to work with more types Instead of special-casing mutable pointers/references, we now support general generic types (currently, we handle `ty::Ref`, `ty::RawPtr`, and `ty::Adt`) When a `ty::Adt` is involved, we show an additional note explaining which of the type's generic parameters is invariant (e.g. the `T` in `Cell<T>`). Currently, we don't explain why a particular generic parameter ends up becoming invariant. In the general case, this could require printing a long 'backtrace' of types, so doing this would be more suitable for a follow-up PR. We still only handle the case where our variance switches to `ty::Invariant`. 2021-09-27 20:22:44 -05:00			`= note: requirement occurs because of the type SomeStruct<&()>, which makes the generic argument &() invariant`
			`= note: the struct SomeStruct<T> is invariant over the parameter T`
			`= help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance`
Change compare mode to use -Zborrowck=mir 2019-01-27 05:03:21 -06:00
			`error: lifetime may not live long enough`
			`--> $DIR/variance-use-invariant-struct-1.rs:19:5`
			`\|`
			`LL \| fn bar<'min,'max>(v: SomeStruct<&'min ()>)`
			\| ---- ---- lifetime `'max` defined here
			`\| \|`
			\| lifetime `'min` defined here
			`...`
			`LL \| v`
Ensure that early-bound function lifetimes are always 'local' During borrowchecking, we treat any free (early-bound) regions on the 'defining type' as `RegionClassification::External`. According to the doc comments, we should only have 'external' regions when checking a closure/generator. However, a plain function can also have some if its regions be considered 'early bound' - this occurs when the region is constrained by an argument, appears in a `where` clause, or in an opaque type. This was causing us to incorrectly mark these regions as 'external', which caused some diagnostic code to act as if we were referring to a 'parent' region from inside a closure. This PR marks all instantiated region variables as 'local' when we're borrow-checking something other than a closure/generator/inline-const. 2021-12-31 15:55:34 -06:00			\| ^ function was supposed to return data with lifetime `'max` but it is returning data with lifetime `'min`
update tests 2019-10-27 09:39:14 -05:00			`\|`
			= help: consider adding the following bound: `'min: 'max`
Refactor variance diagnostics to work with more types Instead of special-casing mutable pointers/references, we now support general generic types (currently, we handle `ty::Ref`, `ty::RawPtr`, and `ty::Adt`) When a `ty::Adt` is involved, we show an additional note explaining which of the type's generic parameters is invariant (e.g. the `T` in `Cell<T>`). Currently, we don't explain why a particular generic parameter ends up becoming invariant. In the general case, this could require printing a long 'backtrace' of types, so doing this would be more suitable for a follow-up PR. We still only handle the case where our variance switches to `ty::Invariant`. 2021-09-27 20:22:44 -05:00			`= note: requirement occurs because of the type SomeStruct<&()>, which makes the generic argument &() invariant`
			`= note: the struct SomeStruct<T> is invariant over the parameter T`
			`= help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance`
Change compare mode to use -Zborrowck=mir 2019-01-27 05:03:21 -06:00
			`error: aborting due to 2 previous errors`