Merge pull request #7550 from jangko/fix4799

fixes #4799, varargs now can accept polymorphic types

compiler/ccgexprs.nim

@@ -351,7 +351,9 @@ proc genAssignment(p: BProc, dest, src: TLoc, flags: TAssignmentFlags) =
     else:
       useStringh(p.module)
       linefmt(p, cpsStmts,
-           "memcpy((void*)$1, (NIM_CONST void*)$2, sizeof($1[0])*$1Len_0);$n",
+           # bug #4799, keep the memcpy for a while
+           #"memcpy((void*)$1, (NIM_CONST void*)$2, sizeof($1[0])*$1Len_0);$n",
+           "$1 = $2;$n",
            rdLoc(dest), rdLoc(src))
   of tySet:
     if mapType(ty) == ctArray:

compiler/sigmatch.nim

@@ -2013,6 +2013,14 @@ proc paramTypesMatchAux(m: var TCandidate, f, a: PType,
           if r == isGeneric:
             result.typ = getInstantiatedType(c, arg, m, base(f))
           m.baseTypeMatch = true
+        # bug #4799, varargs accepting subtype relation object
+        elif r == isSubtype:
+          inc(m.subtypeMatches)
+          if f.kind == tyTypeDesc:
+            result = arg
+          else:
+            result = implicitConv(nkHiddenSubConv, f, arg, m, c)
+          m.baseTypeMatch = true
         else:
           result = userConvMatch(c, m, base(f), a, arg)
           if result != nil: m.baseTypeMatch = true