1 files changed, 32 insertions, 1 deletions
diff --git a/compiler/semexprs.nim b/compiler/semexprs.nim
index 52d1f0628..cb27ca0ff 100644
--- a/compiler/semexprs.nim
+++ b/compiler/semexprs.nim
@@ -1828,6 +1828,37 @@ proc goodLineInfo(arg: PNode): TLineInfo =
   else:
     arg.info
 
+proc makeTupleAssignments(c: PContext; n: PNode): PNode =
+  ## expand tuple unpacking assignment into series of assignments
+  ## 
+  ## mirrored with semstmts.makeVarTupleSection
+  let lhs = n[0]
+  let value = semExprWithType(c, n[1], {efTypeAllowed})
+  if value.typ.kind != tyTuple:
+    localError(c.config, n[1].info, errXExpected, "tuple")
+  elif lhs.len != value.typ.len:
+    localError(c.config, n.info, errWrongNumberOfVariables)
+  result = newNodeI(nkStmtList, n.info)
+
+  let temp = newSym(skTemp, getIdent(c.cache, "tmpTupleAsgn"), c.idgen, getCurrOwner(c), n.info)
+  temp.typ = value.typ
+  temp.flags.incl(sfGenSym)
+  var v = newNodeI(nkLetSection, value.info)
+  let tempNode = newSymNode(temp) #newIdentNode(getIdent(genPrefix & $temp.id), value.info)
+  var vpart = newNodeI(nkIdentDefs, v.info, 3)
+  vpart[0] = tempNode
+  vpart[1] = c.graph.emptyNode
+  vpart[2] = value
+  v.add vpart
+  result.add(v)
+
+  for i in 0..<lhs.len:
+    if lhs[i].kind == nkIdent and lhs[i].ident.id == ord(wUnderscore):
+      # skip _ assignments if we are using a temp as they are already evaluated
+      discard
+    else:
+      result.add newAsgnStmt(lhs[i], newTupleAccessRaw(tempNode, i))
+
 proc semAsgn(c: PContext, n: PNode; mode=asgnNormal): PNode =
   checkSonsLen(n, 2, c.config)
   var a = n[0]
@@ -1870,7 +1901,7 @@ proc semAsgn(c: PContext, n: PNode; mode=asgnNormal): PNode =
       # unfortunately we need to rewrite ``(x, y) = foo()`` already here so
       # that overloading of the assignment operator still works. Usually we
       # prefer to do these rewritings in transf.nim:
-      return semStmt(c, lowerTupleUnpackingForAsgn(c.graph, n, c.idgen, c.p.owner), {})
+      return semStmt(c, makeTupleAssignments(c, n), {})
     else:
       a = semExprWithType(c, a, {efLValue})
   else: