diff options
| -rw-r--r-- | src/librustc/middle/infer/mod.rs | 9 | ||||
| -rw-r--r-- | src/test/run-pass/issue-28550.rs | 25 |
2 files changed, 33 insertions, 1 deletions
diff --git a/src/librustc/middle/infer/mod.rs b/src/librustc/middle/infer/mod.rs index 917727907ba..e21e49ac5c8 100644 --- a/src/librustc/middle/infer/mod.rs +++ b/src/librustc/middle/infer/mod.rs @@ -1389,9 +1389,16 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { self.resolve_type_vars_or_error(&ty) } + pub fn tables_are_tcx_tables(&self) -> bool { + let tables: &RefCell<ty::Tables> = &self.tables; + let tcx_tables: &RefCell<ty::Tables> = &self.tcx.tables; + tables as *const _ == tcx_tables as *const _ + } + pub fn type_moves_by_default(&self, ty: Ty<'tcx>, span: Span) -> bool { let ty = self.resolve_type_vars_if_possible(&ty); - if ty.needs_infer() { + if ty.needs_infer() || + (ty.has_closure_types() && !self.tables_are_tcx_tables()) { // this can get called from typeck (by euv), and moves_by_default // rightly refuses to work with inference variables, but // moves_by_default has a cache, which we want to use in other diff --git a/src/test/run-pass/issue-28550.rs b/src/test/run-pass/issue-28550.rs new file mode 100644 index 00000000000..f44a535e817 --- /dev/null +++ b/src/test/run-pass/issue-28550.rs @@ -0,0 +1,25 @@ +// Copyright 2015 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +struct A<F: FnOnce()->T,T>(F::Output); +struct B<F: FnOnce()->T,T>(A<F,T>); + +// Removing Option causes it to compile. +fn foo<T,F: FnOnce()->T>(f: F) -> Option<B<F,T>> { + Some(B(A(f()))) +} + +fn main() { + let v = (|| foo(||4))(); + match v { + Some(B(A(4))) => {}, + _ => unreachable!() + } +} |