Added "const" accessors to Row

Data/include/Poco/Data/Row.h

@@ -104,6 +104,15 @@ class Data_API Row
 	Poco::Dynamic::Var& operator [] (const std::string& name);
 		/// Returns the reference to data value at named column location.
 
+	const Poco::Dynamic::Var& get(std::size_t col) const;
+	/// Returns the reference to data value at column location.
+
+	const Poco::Dynamic::Var& operator [] (std::size_t col) const;
+	/// Returns the reference to data value at column location.
+
+	const Poco::Dynamic::Var& operator [] (const std::string& name) const;
+	/// Returns the reference to data value at named column location.
+
 	template <typename T>
 	void append(const std::string& name, const T& val)
 		/// Appends the value to the row.
@@ -225,7 +234,7 @@ class Data_API Row
 	ValueVec& values();
 		/// Returns the reference to values vector.
 
-	std::size_t getPosition(const std::string& name);
+	std::size_t getPosition(const std::string& name) const;
 	bool isEqualSize(const Row& other) const;
 	bool isEqualType(const Row& other) const;
 
@@ -287,6 +296,18 @@ inline Poco::Dynamic::Var& Row::operator [] (const std::string& name)
 }
 
 
+inline const Poco::Dynamic::Var& Row::operator [] (std::size_t col) const
+{
+	return get(col);
+}
+
+
+inline const Poco::Dynamic::Var& Row::operator [] (const std::string& name) const
+{
+	return get(getPosition(name));
+}
+
+
 inline const RowFormatter& Row::getFormatter() const
 {
 	return *_pFormatter;

Data/src/Row.cpp

@@ -94,7 +94,20 @@ Poco::Dynamic::Var& Row::get(std::size_t col)
 }
 
 
-std::size_t Row::getPosition(const std::string& name)
+const Poco::Dynamic::Var& Row::get(std::size_t col) const
+{
+	try
+	{
+		return _values.at(col);
+	}
+	catch (std::out_of_range& re)
+	{
+		throw RangeException(re.what());
+	}
+}
+
+
+std::size_t Row::getPosition(const std::string& name) const
 {
 	if (!_pNames)
 		throw NullPointerException();

Data/testsuite/src/DataTest.cpp

@@ -901,6 +901,11 @@ void DataTest::testRow()
 	assert (row[3] == 3);
 	assert (row[4] == 4);
 
+	const Row& cr = row;
+	assert(cr["field0"] == 0);
+	assert(cr[0] == 0);
+	assert(cr.get(0) == 0);
+
 	try
 	{
 		int i; i = row[5].convert<int>(); // to silence gcc