c++ - Undefined reference error for template method

This has been driving me mad for the past hour and a half. I know it's a small thing but cannot find what's wrong (the fact that it's a rainy Friday afternoon, of course, does not help).

I have defined the following class that will hold configuration parameters read from a file and will let me access them from my program:

class VAConfig {
    friend std::ostream& operator<<( std::ostream& lhs, const VAConfig& rhs);
private:
    VAConfig();
    static std::string      configFilename;
    static VAConfig*        pConfigInstance;
    static TiXmlDocument*   pXmlDoc;
    std::map valueHash;
public:
    static VAConfig* getInstance();
    static void setConfigFileName( std::string& filename ) { configFilename = filename; }
    virtual ~VAConfig();
    void readParameterSet( std::string parameterGroupName );
    template T readParameter( const std::string parameterName );
    template T convert( const std::string& value );
};

where the method convert() is defined in VAConfig.cpp as

template 
T VAConfig::convert( const std::string& value )
{
    T t;
    std::istringstream iss( value, std::istringstream::in );
    iss >> t;
    return t;
}

All quite simple. But when I test from my main program using

int y = parameters->convert("5");

I get an undefined reference to 'int VAConfig::convert...' compilation error. Ditto for readParameter().

Looked at a lot of template tutorials but coul not figure this out. Any ideas?