Commit 608d49a

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Check for bound variables when reporting type error

`can_eq` ICEs if it's passed types with escaping bound variables, so we need to handle for them, even in error reporting.

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+69

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Lines changed: 16 additions & 9 deletions

Original file line number	Diff line number	Diff line change
`@@ -4076,16 +4076,23 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {`
`4076`	`4076`	`})`
`4077`	`4077`	`} else if let Some(where_pred) = where_pred.as_projection_clause()`
`4078`	`4078`	`&& let Some(failed_pred) = failed_pred.as_projection_clause()`
`4079`		`- && let Some(found) = failed_pred.skip_binder().term.as_type()`
`4080`	`4079`	`{`
`4081`		`- type_diffs = vec![TypeError::Sorts(ty::error::ExpectedFound {`
`4082`		`- expected: where_pred`
`4083`		`- .skip_binder()`
`4084`		`- .projection_term`
`4085`		`- .expect_ty(self.tcx)`
`4086`		`- .to_ty(self.tcx),`
`4087`		`- found,`
`4088`		`- })];`
	`4080`	`+ self.enter_forall(failed_pred, \|failed_pred\| {`
	`4081`	`+ if let Some(found) = failed_pred.term.as_type() {`
	`4082`	`+ let where_pred = self.instantiate_binder_with_fresh_vars(`
	`4083`	`+ expr.span,`
	`4084`	`+ BoundRegionConversionTime::HigherRankedType,`
	`4085`	`+ where_pred,`
	`4086`	`+ );`
	`4087`	`+ type_diffs = vec![TypeError::Sorts(ty::error::ExpectedFound {`
	`4088`	`+ expected: where_pred`
	`4089`	`+ .projection_term`
	`4090`	`+ .expect_ty(self.tcx)`
	`4091`	`+ .to_ty(self.tcx),`
	`4092`	`+ found,`
	`4093`	`+ })];`
	`4094`	`+ }`
	`4095`	`+ });`
`4089`	`4096`	`}`
`4090`	`4097`	`}`
`4091`	`4098`	`if let hir::ExprKind::Path(hir::QPath::Resolved(None, path)) = expr.kind`

Lines changed: 22 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,22 @@`
	`1`	`+// Regression test for #145631`
	`2`	`+`
	`3`	`+pub struct Foo {}`
	`4`	`+`
	`5`	`+fn foo(foos: Vec<Foo>) {`
	`6`	`+ let foos = foos.iter().collect::<Vec<_>>();`
	`7`	`+ let bar = Bar {};`
	`8`	`+ bar.bar(foos);`
	`9`	+ //~^ ERROR type mismatch resolving `<&Vec<&Foo> as IntoIterator>::Item == &Foo`
	`10`	`+}`
	`11`	`+`
	`12`	`+struct Bar {}`
	`13`	`+`
	`14`	`+impl Bar {`
	`15`	`+ pub fn bar<I>(&self, iter: I)`
	`16`	`+ where`
	`17`	`+ for<'a> &'a I: IntoIterator<Item = &'a Foo>,`
	`18`	`+ {`
	`19`	`+ }`
	`20`	`+}`
	`21`	`+`
	`22`	`+fn main() {}`

Lines changed: 31 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,31 @@`
	`1`	+error[E0271]: type mismatch resolving `<&Vec<&Foo> as IntoIterator>::Item == &Foo`
	`2`	`+ --> $DIR/mismatched-bound-projection-predicate.rs:8:13`
	`3`	`+ \|`
	`4`	`+LL \| bar.bar(foos);`
	`5`	+ \| --- ^^^^ expected `&Foo`, found `&&Foo`
	`6`	`+ \| \|`
	`7`	`+ \| required by a bound introduced by this call`
	`8`	`+ \|`
	`9`	+ = note: expected reference `&Foo`
	`10`	+ found reference `&&Foo`
	`11`	`+note: the method call chain might not have had the expected associated types`
	`12`	`+ --> $DIR/mismatched-bound-projection-predicate.rs:6:21`
	`13`	`+ \|`
	`14`	`+LL \| fn foo(foos: Vec<Foo>) {`
	`15`	+ \| -------- `IntoIterator::Item` is `Foo` here
	`16`	`+LL \| let foos = foos.iter().collect::<Vec<_>>();`
	`17`	+ \| ^^^^^^ ------------------- `IntoIterator::Item` remains `&Foo` here
	`18`	`+ \| \|`
	`19`	+ \| `IntoIterator::Item` changed to `&Foo` here
	`20`	+note: required by a bound in `Bar::bar`
	`21`	`+ --> $DIR/mismatched-bound-projection-predicate.rs:17:37`
	`22`	`+ \|`
	`23`	`+LL \| pub fn bar<I>(&self, iter: I)`
	`24`	`+ \| --- required by a bound in this associated function`
	`25`	`+LL \| where`
	`26`	`+LL \| for<'a> &'a I: IntoIterator<Item = &'a Foo>,`
	`27`	+ \| ^^^^^^^^^^^^^^ required by this bound in `Bar::bar`
	`28`	`+`
	`29`	`+error: aborting due to 1 previous error`
	`30`	`+`
	`31`	+For more information about this error, try `rustc --explain E0271`.

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