On 06/04/12 09:04, Andrzej Krzemienski wrote:
And this is the worst part: I forgot the "typename". Having to type this "typename" is really terrible and just scares off many people. If you do not mind it, it only means that you got used to it; but people should not be forced to get used to too many gotchas.
The language requires to specify whenever dependent names in template contexts are anything else than values (i.e. types or templates).
There is no substitute for learning the basics of the language. This is not a gotcha, just normal usage of templates.
Clearly, if you do not find requiring of the programmers to type this "typename" in these places even slightly wrong, you will not appreciate alias templates as a useful addition to meta-programming. Also, if you did a lot of advanced meta-programming, you have probably mastered the rules of template syntax, and find it difficult to sympathize with those that did not master the subject. But looking at it from the fresh programmer's perspective, the fact that the language requires "to specify whenever dependent names in template contexts are anything else than values" means that the language is not friendly to the fresh programmers (I understand that there are good reasons for requiring this, but still...). Based on the Wkipedia's definition of "gotcha" I interpret this typename as one. "In programming, a gotcha is a feature of a system, a program or a programming language that works in the way it is documented but is counter-intuitive and almost invites mistakes because it is both enticingly easy to invoke and completely unexpected and/or unreasonable in its outcome." It (the usage of typename) only appears as "normal usage" after you are past the stage of surprise. The context of your reply seems to imply that whoever finds this behavior surprising is guilty of not having acquired the basics of the language. Unless I misunderstood you, I think this position is a bit unfair. Regards, &rzej