From ee6a46f264d41de1d252d1b7e669b7656211a498 Mon Sep 17 00:00:00 2001
From: Andreas Rumpf <rumpf_a@web.de>
Date: Mon, 8 Feb 2016 01:43:38 +0100
Subject: [PATCH] some progress on #3832

---
 compiler/parampatterns.nim | 3 +++
 compiler/semcall.nim       | 8 +++++++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/compiler/parampatterns.nim b/compiler/parampatterns.nim
index 978583c14e..f8f1f355cc 100644
--- a/compiler/parampatterns.nim
+++ b/compiler/parampatterns.nim
@@ -182,6 +182,9 @@ proc isAssignable*(owner: PSym, n: PNode; isUnsafeAddr=false): TAssignableResult
   ## 'owner' can be nil!
   result = arNone
   case n.kind
+  of nkEmpty:
+    if n.typ != nil and n.typ.kind == tyVar:
+      result = arLValue
   of nkSym:
     let kinds = if isUnsafeAddr: {skVar, skResult, skTemp, skParam, skLet}
                 else: {skVar, skResult, skTemp}
diff --git a/compiler/semcall.nim b/compiler/semcall.nim
index a0d0db3ad6..eba1059ef1 100644
--- a/compiler/semcall.nim
+++ b/compiler/semcall.nim
@@ -420,7 +420,13 @@ proc searchForBorrowProc(c: PContext, startScope: PScope, fn: PSym): PSym =
     let param = fn.typ.n.sons[i]
     let t = skipTypes(param.typ, abstractVar-{tyTypeDesc})
     if t.kind == tyDistinct or param.typ.kind == tyDistinct: hasDistinct = true
-    call.add(newNodeIT(nkEmpty, fn.info, t.baseOfDistinct))
+    var x: PType
+    if param.typ.kind == tyVar:
+      x = newTypeS(tyVar, c)
+      x.addSonSkipIntLit t.baseOfDistinct
+    else:
+      x = t.baseOfDistinct
+    call.add(newNodeIT(nkEmpty, fn.info, x))
   if hasDistinct:
     var resolved = semOverloadedCall(c, call, call, {fn.kind})
     if resolved != nil: