Just take a look at boost::variant data structure. It allows you to store _one_ of enumerated types in the container. If you try to put some not registered type instance into it you will get a compiler error. I think this data structure is pretty cool. What if such a variant<types 1...n> represents a communication protocol which can contain one of enumerated message type instance. In this case the sender can not put there a message (per-compiler) which should not be there (not allowed). And a receiver can be 100% sure that it will not receive a message which should not be handled. With Kind Regards, Ovanes Markarian On Tue, October 17, 2006 04:49, Terry G wrote:
I've just finished reading C++ Template Metaprogramming again. I just don't get it.
Why would someone use a type container?
I have used enable_if, along with some of the logic functions for managing an overload set. Otherwise, I'm clueless.
I'd really like a reference to an MPL primer or some case studies.
Too much pain with very little gain. Time to ask for help. Rereading this, it sounds negative. Really, I think the MPL is really cool!
terry
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