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| author | Mazdak Farrokhzad <twingoow@gmail.com> | 2019-09-15 02:49:37 +0200 |
|---|---|---|
| committer | Mazdak Farrokhzad <twingoow@gmail.com> | 2019-09-15 18:50:44 +0200 |
| commit | 4c346939b088cf07ece818b7dc093f993eae2578 (patch) | |
| tree | 0e6ee5a299c993ada647da80b1bbcea48cca549a | |
| parent | 89bbef302646c4b33148e2a34b69de7643a55ffa (diff) | |
| download | rust-4c346939b088cf07ece818b7dc093f993eae2578.tar.gz rust-4c346939b088cf07ece818b7dc093f993eae2578.zip | |
or-patterns: fix problems in typeck.
| -rw-r--r-- | src/librustc_typeck/check/pat.rs | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/src/librustc_typeck/check/pat.rs b/src/librustc_typeck/check/pat.rs index 8502b89de14..c8869132fb6 100644 --- a/src/librustc_typeck/check/pat.rs +++ b/src/librustc_typeck/check/pat.rs @@ -97,11 +97,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { self.check_pat_struct(pat, qpath, fields, *etc, expected, def_bm, discrim_span) } PatKind::Or(pats) => { - let expected_ty = self.structurally_resolved_type(pat.span, expected); for pat in pats { self.check_pat(pat, expected, def_bm, discrim_span); } - expected_ty + expected } PatKind::Tuple(elements, ddpos) => { self.check_pat_tuple(pat.span, elements, *ddpos, expected, def_bm, discrim_span) @@ -208,7 +207,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { match pat.node { PatKind::Struct(..) | PatKind::TupleStruct(..) | - PatKind::Or(_) | PatKind::Tuple(..) | PatKind::Box(_) | PatKind::Range(..) | @@ -226,6 +224,18 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { _ => true, } } + // FIXME(or_patterns; Centril | dlrobertson): To keep things compiling + // for or-patterns at the top level, we need to make `p_0 | ... | p_n` + // a "non reference pattern". For example the following currently compiles: + // ``` + // match &1 { + // e @ &(1...2) | e @ &(3...4) => {} + // _ => {} + // } + // ``` + // + // We should consider whether we should do something special in nested or-patterns. + PatKind::Or(_) | PatKind::Wild | PatKind::Binding(..) | PatKind::Ref(..) => false, @@ -426,12 +436,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { // If the binding is like `ref x | ref const x | ref mut x` // then `x` is assigned a value of type `&M T` where M is the // mutability and T is the expected type. - let region_ty = self.new_ref_ty(pat.span, mutbl, expected); - + // // `x` is assigned a value of type `&M T`, hence `&M T <: typeof(x)` // is required. However, we use equality, which is stronger. // See (note_1) for an explanation. - region_ty + self.new_ref_ty(pat.span, mutbl, expected) } // Otherwise, the type of x is the expected type `T`. ty::BindByValue(_) => { |