On 9/3/2012 4:01 PM, Ilya Bobyr wrote:
On 9/2/2012 1:46 PM, Vicente J. Botet Escriba wrote:
[...] I managed defining a specific opaque type, let me say MyGreek, and defining implicit conversions from these types.
Your example could be written as
std::cout << string(MyGreek(1)) << std::endl; std::cout << string(MyGreek(6)) << std::endl; std::cout << MyGreek(Alpha) << std::endl; std::cout << MyGreek::Alpha << std::endl; // using nested literal std::cout << string(MyGreek(Alpha)) << std::endl; std::cout << string(MyGreek::Alpha) << std::endl; // using nested literal std::cout << MyGreek(17) << std::endl;
If think this interface corresponds more to how C++ conversions work (IMO of course).
(Or does boost even offer something like that already?) I don't think so. The closest could be TBoost.Enums in the sandbox, but this library generates the enum and don't do the mapping.
I think that it can do both plain enums and enums that map to arbitrary types. Here is an example where string are associated with enum values:
http://stackoverflow.com/a/439004
The syntax is different but the function is the same.
BOOST_ENUM_VALUES(Greek, int, (Alpha)(5), (Beta)(3), (Gamma)(7), (Delta)(1), (Epsilon)(6) );
/* class Greek { ... typedef boost::optional<Greek> optional; ... */
Greek::optional gammaVal = Greek::get_by_name("Gamma"); s/Level/Greek/g
And the other way around: if (gammaVal) const char * gammaName = gammaVal->str(); You can also do Greek::optional gammaVal = Greek::get_by_value(7); P.S. Sorry for the two emails instead of one. -- Ilya Bobyr