Gregory Dai wrote: [snip]
As usual, the latest documentation is here:
http://www.revergestudios.com/boost-exception/boost-exception.htm
Here is a zip file with the source code, complete with jamfiles and tests:
http://www.revergestudios.com/boost-exception/boost-exception.zip [snip] The current implementation generates a string representation of each exception info value (at the time exception_info is called) as follows:
- If a suitable overload for the unqualified call to to_string (passing the exception info value as the only argument) is found, that overload is used.
- Otherwise, if a suitable overload for serializing the exception info value into a std::ostringstream is found, that overload is used.
- Otherwise the system gives up and uses a generic "stub" string to indicate that the exception info value could not be converted to string.
This is accomplished through the to_string function template, which has the following signature:
template <class T> std::string to_string( T const &, char const * stub );
Do you think that to_string is universally useful? Is there anything in Boost with similar functionality? Perhaps we can make to_string a separate addition to Boost?
std::string s = boost::lexical_cast<std::string>(T const&);
This will not work because it requires that a conversion from T to std::string is available. The main use of the exception library is for storing values in exception objects, both at the time of the throw, and after a catch and before a re-throw. Purely for logging/debugging purposes, the exception lib can automatically generate a string that represents all values stored in an exception object, but it isn't reasonable to require that a conversion to string is defined for each type users can store in exception objects. The way the exception lib defines to_string, it will do what boost::lexical_cast does if such conversion is available; if the type can not be converted to string, this does not result in compile error, and a "stub" string representation is used instead (the definition of to_string is in to_string.hpp in the linked .ZIP file above.) So let me change my original question about to_string being useful by itself: isn't it a good idea to include in Boost something like to_string (or some form of lexical_cast<std::string>) that does not result in a compile error in the case when the conversion is not possible? --Emil