Merge pull request #358 from redboltz/fix_357

Fixed #357.

Author: redboltz

include/msgpack/object.hpp

@@ -511,6 +511,16 @@ inline T* object::convert(T* v) const
     return v;
 }
 
+template <typename T>
+inline bool object::convert_if_not_nil(T& v) const
+{
+    if (is_nil()) {
+        return false;
+    }
+    convert(v);
+    return true;
+}
+
 #if defined(MSGPACK_USE_CPP03)
 
 template <typename T>

include/msgpack/object_fwd.hpp

@@ -149,6 +149,9 @@ struct object {
     template <typename T>
     T* convert(T* v) const;
 
+    template <typename T>
+    bool convert_if_not_nil(T& v) const;
+
     object();
 
     object(const msgpack_object& o);

test/convert.cpp

@@ -93,3 +93,20 @@ TEST(convert, return_value_ref)
     EXPECT_EQ(&i, &j);
     EXPECT_EQ(i, j);
 }
+
+TEST(convert, if_not_nil_nil)
+{
+    msgpack::object obj;
+    int i;
+    EXPECT_FALSE(obj.convert_if_not_nil(i));
+}
+
+TEST(convert, if_not_nil_not_nil)
+{
+    msgpack::zone z;
+    msgpack::object obj(1, z);
+
+    int i;
+    EXPECT_TRUE(obj.convert_if_not_nil(i));
+    EXPECT_EQ(i, 1);
+}