diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/comp/middle/ty.rs | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/src/comp/middle/ty.rs b/src/comp/middle/ty.rs index 59de7768..96479c40 100644 --- a/src/comp/middle/ty.rs +++ b/src/comp/middle/ty.rs @@ -2362,9 +2362,15 @@ mod Unify { auto ures = unify_step(cx, expected, actual); alt (ures) { - case (ures_ok(?t)) { + case (ures_ok(?typ)) { + // Fast path: if there are no local variables, don't perform + // substitutions. + if (_vec.len[mutable UFind.node](cx.sets.nodes) == 0u) { + ret ures_ok(typ); + } + auto set_types = unify_sets(cx); - auto t2 = substitute(cx, set_types, t); + auto t2 = substitute(cx, set_types, typ); ret ures_ok(t2); } case (_) { ret ures; } |