Add a type_is_tup_like predicate that takes a block ctxt, and make some fns pure

Author: catamorphism

src/comp/middle/trans_common.rs

@@ -449,14 +449,14 @@ fn find_scope_cx(cx: @block_ctxt) -> @block_ctxt {
 // Accessors
 // TODO: When we have overloading, simplify these names!
 
-fn bcx_tcx(bcx: @block_ctxt) -> ty::ctxt { ret bcx.fcx.lcx.ccx.tcx; }
-fn bcx_ccx(bcx: @block_ctxt) -> @crate_ctxt { ret bcx.fcx.lcx.ccx; }
-fn bcx_lcx(bcx: @block_ctxt) -> @local_ctxt { ret bcx.fcx.lcx; }
-fn bcx_fcx(bcx: @block_ctxt) -> @fn_ctxt { ret bcx.fcx; }
-fn fcx_ccx(fcx: @fn_ctxt) -> @crate_ctxt { ret fcx.lcx.ccx; }
-fn fcx_tcx(fcx: @fn_ctxt) -> ty::ctxt { ret fcx.lcx.ccx.tcx; }
-fn lcx_ccx(lcx: @local_ctxt) -> @crate_ctxt { ret lcx.ccx; }
-fn ccx_tcx(ccx: @crate_ctxt) -> ty::ctxt { ret ccx.tcx; }
+pure fn bcx_tcx(bcx: @block_ctxt) -> ty::ctxt { bcx.fcx.lcx.ccx.tcx }
+pure fn bcx_ccx(bcx: @block_ctxt) -> @crate_ctxt { bcx.fcx.lcx.ccx }
+pure fn bcx_lcx(bcx: @block_ctxt) -> @local_ctxt { bcx.fcx.lcx }
+pure fn bcx_fcx(bcx: @block_ctxt) -> @fn_ctxt { bcx.fcx }
+pure fn fcx_ccx(fcx: @fn_ctxt) -> @crate_ctxt { fcx.lcx.ccx }
+pure fn fcx_tcx(fcx: @fn_ctxt) -> ty::ctxt { fcx.lcx.ccx.tcx }
+pure fn lcx_ccx(lcx: @local_ctxt) -> @crate_ctxt { lcx.ccx }
+pure fn ccx_tcx(ccx: @crate_ctxt) -> ty::ctxt { ccx.tcx }
 
 // LLVM type constructors.
 fn T_void() -> TypeRef {
@@ -861,6 +861,11 @@ pure fn returns_non_ty_var(cx: @crate_ctxt, t: ty::t) -> bool {
     non_ty_var(cx, ty::ty_fn_ret(cx.tcx, t))
 }
 
+pure fn type_is_tup_like(cx: @block_ctxt, t: ty::t) -> bool {
+    let tcx = bcx_tcx(cx);
+    ty::type_is_tup_like(tcx, t)
+}
+
 //
 // Local Variables:
 // mode: rust

src/comp/middle/ty.rs

@@ -832,13 +832,11 @@ fn sequence_element_type(cx: ctxt, ty: t) -> t {
     }
 }
 
-fn type_is_tup_like(cx: ctxt, ty: t) -> bool {
-    alt struct(cx, ty) {
-      ty_box(_) { ret true; }
-      ty_rec(_) { ret true; }
-      ty_tup(_) { ret true; }
-      ty_tag(_, _) { ret true; }
-      _ { ret false; }
+pure fn type_is_tup_like(cx: ctxt, ty: t) -> bool {
+    let sty = unchecked { struct(cx, ty) };
+    alt sty {
+      ty_box(_) | ty_rec(_) | ty_tup(_) | ty_tag(_,_) { true }
+      _ { false }
     }
 }