# Boost Exception

## Diagnostic Information

Boost Exception provides a namespace-scope function diagnostic_information which takes a boost::exception. The returned string contains:

- the string representation of all data objects added to the boost::exception through operator<<;
- the output from std::exception::what;
- additional platform-specific diagnostic information.

The returned string is not presentable as a friendly user message, but because it is generated automatically, it is useful for debugging or logging purposes. Here is an example:

    #include <boost/exception.hpp>
    #include <iostream>

    void f(); //throws unknown types that derive from boost::exception.

    void
    g()
        {
        try
            {
            f();
            }
        catch(
        boost::exception & e )
            {
            std::cerr << diagnostic_information(e);
            }
        }

### See Also:

Boost Exception