Can't catch my exception

Question

I've created the following exception class(es):

namespace json {

    /**
     * @brief Base class for all json-related exceptions
     */
    class Exception : public std::exception { };

    /**
     * @brief Indicates an internal exception of the json parser
     */
    class InternalException : public Exception {

    public:
        /**
         * @brief Constructs a new InternalException
         *
         * @param msg The message to return on what()
         */
        InternalException( const std::string& msg );
        ~InternalException() throw ();

        /**
         * @brief Returns a more detailed error message
         *
         * @return The error message
         */
        virtual const char* what() const throw();

    private:
        std::string _msg;

    };
}

Implementations(s):

InternalException::InternalException( const std::string& msg ) : _msg( msg ) { }
InternalException::~InternalException() throw () { };

const char* InternalException::what() const throw() {
    return this->_msg.c_str();
}

I throw the exception like this:

throw json::InternalException( "Cannot serialize uninitialized nodes." );

I wanted to test the exception-throwing behaviour in a Boost::Test unit test:

// [...]
BOOST_CHECK_THROW( json::write( obj ), json::InternalException );  //will cause a json::InternalException

However, the test exits when the exception occurs as if there was no try...catch.

If I make the try...catch explicit and surround the json::write() call with try{ json.write(obj); }catch(const json::InternalException& ex){} or even try{json.write(obj);}catch(...){}, I get the same behaviour. The exception is raised, but I can't catch it no matter what.

The output I get is the following:

terminate called after throwing an instance of 'json::InternalException'
what():  Cannot serialize uninitialized nodes.

What am I doing wrong here?

Answer 1

I found it. I figured it out while trying to throw an SSCCE together for you guys. I had json::write() declared with a throw specifier, but didn't include json::InternalException.

Adjusting the throw specifier to the correct exception now lets me actually catch it. Thanks for all the hints.