I tried to put together all, that had been said in this thread, and I prepared boost/utility/safe_bool.hpp (attached). I haven't tested it yet. I took compiler workarounds from <boost/smart_ptr/detail/operator_bool.hpp> To view the file online: http://codepaste.net/c83uuj The file contains the following safe-bool tools: - a CRTP class save_bool_convertilbe<Derived,Base=*,Policy=*>, that implements a conversion operator to a safe-bool in terms of operator! by default, and can be customized by a policy, - a safe_bool_t<tag> - a safe-bool type, implemented in terms of safe_bool_convertible, - 3 macros for defining operator safe-bool inside a class: - BOOST_OPERATOR_SAFE_BOOL_TAGGED(tag,expr) - implemented in terms of safe_bool_t<tag>, - BOOST_OPERATOR_SAFE_BOOL(expr) - which introduces a tag, and is implemented in terms of BOOST_OPERATOR_SAFE_BOOL_TAGGED, - BOOST_EXPLICIT_OPERATOR_BOOL(expr) - which implements an explicit conversion to bool if available, or falls back to BOOST_OPERATOR_SAFE_BOOL otherwise.
From what had been seid in this thread, I understand, that there is interest in all of the above safe-bool tools.
So, does each of these tools deserve its place in boost? Maybe they need to be renamed? What did I miss in the implementation? Regards Kris