C# std::wstring director support

Updates for #1706

Examples/test-suite/csharp/director_wstring_runme.cs

@@ -17,10 +17,19 @@ public class runme
         if (b.get_first() != "hello world!")
             throw new ApplicationException("Incorrect get_first:" + b.get_first());
 
+        /*
         b.call_process_func();
-
         if (b.smem != "hello")
             throw new ApplicationException("Incorrect smem:" + b.smem);
+            */
+
+        b.call_process_wstring_func();
+        if (b.smem != "hello (wstring)")
+            throw new ApplicationException("Incorrect smem:" + b.smem);
+
+        b.call_process_wstring_ref_func();
+        if (b.smem != "hello (wstring ref)")
+            throw new ApplicationException("Incorrect smem:" + b.smem);
     }
 }
 
@@ -38,4 +47,12 @@ class director_wstring_B : A
     {
         this.smem = s;
     }
-}
+    public override void process_wstring_text(String s)
+    {
+        this.smem = s + " (wstring)";
+    }
+    public override void process_wstring_ref_text(String s)
+    {
+        this.smem = s + " (wstring ref)";
+    }
+}

Examples/test-suite/director_wstring.i

@@ -41,13 +41,12 @@ struct A
 
 
 #if !defined(SWIGCSHARP)
-  virtual void process_text(const wchar_t *text) 
+  virtual void process_text(const wchar_t *text) {}
-  {
-  }
 #else
-  virtual void process_text(const std::wstring& text)
+// temp until wchar_t* fixed
-  {
+  virtual void process_text(std::wstring text) {}
-  }
+  virtual void process_wstring_text(std::wstring text) {}
+  virtual void process_wstring_ref_text(const std::wstring& text) {}
 #endif
 
   virtual std::wstring multiple_params_val(const std::wstring& p1, const std::wstring& p2, std::wstring p3, std::wstring p4) const
@@ -57,6 +56,8 @@ struct A
   { return get_first(); }
   
   void call_process_func() { process_text(L"hello"); }
+  void call_process_wstring_func() { process_wstring_text(L"hello"); }
+  void call_process_wstring_ref_func() { process_wstring_ref_text(L"hello"); }
  };
  
  %}

Lib/csharp/std_wstring.i

@@ -70,7 +70,7 @@ class wstring;
     SWIG_CSharpSetPendingExceptionArgument(SWIG_CSharpArgumentNullException, "null wstring", 0);
     return $null;
    }
-   $result.assign($input); %}
+   $result = Swig_csharp_UTF16ToWString($input); %}
 
 %typemap(directorin) wstring %{ $input = SWIG_csharp_wstring_with_length_callback($1.c_str(), (int)$1.size()); %}
 
@@ -121,10 +121,10 @@ class wstring;
    }
    /* possible thread/reentrant code problem */
    static std::wstring $1_str;
-   $1_str = $input;
+   $1_str = Swig_csharp_UTF16ToWString($input);
    $result = &$1_str; %}
 
-%typemap(directorin) const wstring & %{ $input = SWIG_csharp_wstring_with_length_callback($1.c_str(), (int)$1->size()); %}
+%typemap(directorin) const wstring & %{ $input = SWIG_csharp_wstring_with_length_callback($1.c_str(), (int)$1.size()); %}
 
 %typemap(csvarin, excode=SWIGEXCODE2) const wstring & %{
     set {