diff options
| -rw-r--r-- | src/rustc/middle/ty.rs | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/src/rustc/middle/ty.rs b/src/rustc/middle/ty.rs index 5afc60f58ac..109db9ace09 100644 --- a/src/rustc/middle/ty.rs +++ b/src/rustc/middle/ty.rs @@ -1093,12 +1093,15 @@ pure fn mach_sty(cfg: @session::config, t: t) -> sty { } fn default_arg_mode_for_ty(tcx: ctxt, ty: ty::t) -> ast::rmode { - return if type_is_fn(ty) { - // ^^^^^^^^^^^^^^ - // FIXME(#2202) --- We retain by-ref by default to workaround a memory - // leak that otherwise results when @fn is upcast to &fn. - ast::by_ref - } else if tcx.legacy_modes { + // FIXME(#2202) --- We retain by-ref for fn& things to workaround a + // memory leak that otherwise results when @fn is upcast to &fn. + if type_is_fn(ty) { + match ty_fn_proto(ty) { + proto_vstore(vstore_slice(_)) => return ast::by_ref, + _ => () + } + } + return if tcx.legacy_modes { if type_is_borrowed(ty) { // the old mode default was ++ for things like &ptr, but to be // forward-compatible with non-legacy, we should use + |