Le 23/10/13 13:10, Piotr Wygocki a écrit :
Than you for your feedback!
Are you aware of Boost.Phoenix ( or its predecessor Boost.Lambda ) ? Also some of the functors appear to duplicate functors in the C++ standard library in functional.
1) This is good point, this functors are for this kind of people who like lambdas.
Many of proposed functors are equivalent to very simple lambdas. For example: ArrayToFunction can be replaced in most cases replaced with
auto arrayToFunction = [&](int i){ return v[i];};
or
auto arrayToFunction = phoenix::ref(v)[_1];
In this case my proposal is to standarize this kind of popular usage: auto arrayToFunction = make_ArrayToFunctor(v); Popularity is subjective. 2) There is another use case for people who like passing functors and need default arguments.
For example my SkipFunctor does exactly the same job as phoenix::nothing. For example my RetrunFalseFunctor does exactly the same job as phoenix::val(true).
Look at this use case:
template <typename SomeAction = SkipFunctor, typename StopCondidtion = ReturnFalseFunctor> struct Algorithm {
};
AFAIK it cannot be replaced with phoenix construction because we do not have the type of the nothing functor. Particularly, note that decltype(phoenix::nothing) is not going to work.
This is tiny difference but this play a big role in a code I write.
What about adding phoenix::true_/phoenix::false_?
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