diff options
Diffstat (limited to 'src/librustc/middle/const_eval.rs')
| -rw-r--r-- | src/librustc/middle/const_eval.rs | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/src/librustc/middle/const_eval.rs b/src/librustc/middle/const_eval.rs index 8c7c8eda2d2..98d2cefac0f 100644 --- a/src/librustc/middle/const_eval.rs +++ b/src/librustc/middle/const_eval.rs @@ -28,6 +28,7 @@ use syntax::visit; use syntax::{ast, ast_map, ast_util}; use std::rc::Rc; +use std::collections::hashmap::Vacant; // // This pass classifies expressions by their constant-ness. @@ -321,7 +322,10 @@ pub fn const_expr_to_pat(tcx: &ty::ctxt, expr: &Expr) -> P<Pat> { ExprCall(ref callee, ref args) => { let def = tcx.def_map.borrow().get_copy(&callee.id); - tcx.def_map.borrow_mut().find_or_insert(expr.id, def); + match tcx.def_map.borrow_mut().entry(expr.id) { + Vacant(entry) => { entry.set(def); } + _ => {} + }; let path = match def { def::DefStruct(def_id) => def_to_path(tcx, def_id), def::DefVariant(_, variant_did, _) => def_to_path(tcx, variant_did), |