Add templated accessors for C string

include/rapidjson/document.h

@@ -401,7 +401,7 @@ namespace internal {
 template <typename ValueType, typename T>
 struct TypeHelper {
     static bool Is(const ValueType&) { RAPIDJSON_ASSERT(false && "Unsupport type"); }
-    static T Get(const ValueType&) { RAPIDJSON_ASSERT(false && "Unsupport type"); }
+    static T Get(const ValueType&) { RAPIDJSON_ASSERT(false && "Unsupport type"); return T(); }
     static ValueType& Set(ValueType&, T) { RAPIDJSON_ASSERT(false && "Unsupport type"); }
     static ValueType& Set(ValueType&, T, typename ValueType::AllocatorType&) { RAPIDJSON_ASSERT(false && "Unsupport type"); }
 };
@@ -462,6 +462,15 @@ struct TypeHelper<ValueType, float> {
     static ValueType& Set(ValueType& v, float data, typename ValueType::AllocatorType&) { return v.SetFloat(data); }
 };
 
+template<typename ValueType> 
+struct TypeHelper<ValueType, const typename ValueType::Ch*> {
+    typedef const typename ValueType::Ch* StringType;
+    static bool Is(const ValueType& v) { return v.IsString(); }
+    static StringType Get(const ValueType& v) { return v.GetString(); }
+    static ValueType& Set(ValueType& v, const StringType data) { return v.SetString(typename ValueType::StringRefType(data)); }
+    static ValueType& Set(ValueType& v, const StringType data, typename ValueType::AllocatorType& a) { return v.SetString(data, a); }
+};
+
 #if RAPIDJSON_HAS_STDSTRING
 template<typename ValueType> 
 struct TypeHelper<ValueType, std::basic_string<typename ValueType::Ch> > {
@@ -1561,10 +1570,10 @@ public:
         RAPIDJSON_ASSERT((flags_ & kUint64Flag) != 0);  return static_cast<double>(data_.n.u64); // uint64_t -> double (may lose precision)
     }
 
-    //! Get the value as double type.
+    //! Get the value as float type.
     /*! \note If the value is 64-bit integer type, it may lose precision. Use \c IsLosslessFloat() to check whether the converison is lossless.
     */
-    double GetFloat() const {
+    float GetFloat() const {
         RAPIDJSON_ASSERT(IsFloat());
         return static_cast<float>(GetDouble());
     }

test/unittest/valuetest.cpp

@@ -768,6 +768,11 @@ TEST(Value, String) {
     EXPECT_STREQ("World", w.GetString());
     EXPECT_EQ(5u, w.GetStringLength());
 
+    // templated functions
+    EXPECT_TRUE(z.Is<const char*>());
+    EXPECT_STREQ(cstr, z.Get<const char*>());
+    EXPECT_STREQ("Apple", z.Set<const char*>("Apple").Get<const char*>());
+
 #if RAPIDJSON_HAS_STDSTRING
     {
         std::string str = "Hello World";