From 4164ec4f8b6d9968e69381edd35d9cf6fe79dee1 Mon Sep 17 00:00:00 2001
From: cooldome <cdome@bk.ru>
Date: Fri, 2 Mar 2018 11:14:41 +0000
Subject: [PATCH] Fixes #6837 (#7271)

---
 compiler/ccgstmts.nim   |  5 ++++-
 tests/cpp/temitlist.nim | 16 +++++++++++++++-
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/compiler/ccgstmts.nim b/compiler/ccgstmts.nim
index a69495a4b7..6b8ba2b025 100644
--- a/compiler/ccgstmts.nim
+++ b/compiler/ccgstmts.nim
@@ -243,7 +243,10 @@ proc genSingleVar(p: BProc, a: PNode) =
           if params != nil: params.add(~", ")
           assert(sonsLen(typ) == sonsLen(typ.n))
           add(params, genOtherArg(p, value, i, typ))
-        lineF(p, cpsStmts, "$#($#);$n", [decl, params])
+        if params == nil:
+          lineF(p, cpsStmts, "$#;$n", [decl])
+        else:
+          lineF(p, cpsStmts, "$#($#);$n", [decl, params])
       else:
         initLocExprSingleUse(p, value, tmp)
         lineF(p, cpsStmts, "$# = $#;$n", [decl, tmp.rdLoc])
diff --git a/tests/cpp/temitlist.nim b/tests/cpp/temitlist.nim
index a7a8ebde47..e88bf45bd4 100644
--- a/tests/cpp/temitlist.nim
+++ b/tests/cpp/temitlist.nim
@@ -1,6 +1,7 @@
 discard """
   targets: "cpp"
-  output: '''6.0'''
+  output: '''6.0
+0'''
 """
 
 # bug #4730
@@ -20,3 +21,16 @@ proc main =
   echo v[0]
 
 main()
+
+#------------
+
+#bug #6837
+type StdString {.importCpp: "std::string", header: "<string>", byref.} = object
+proc initString(): StdString {.constructor, importCpp: "std::string(@)", header: "<string>".}
+proc size(this: var StdString): csize {.importCpp: "size", header: "<string>".}
+
+proc f(): csize =
+  var myString: StdString = initString()
+  return myString.size()
+
+echo f()