Re: [Boost-users] [phoenix][lambda] lambda to phoenix translation: get arguments from expression

On 5/29/2010 3:48 PM, alfC wrote:

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with boost.lambda I could extract the different components (Lambda and the actual value stored by value<double>) from f_expr as: get<0>(f_expr.args) //for lambda and get<1>(get<1>(f_expr.args).args) //for lambda

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what is the equivalent for Boost.phoenix?,

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Check out the extension mechanism (somewhere near the end) where this is documented. See composites. Essentially, while lambda uses tuples, phoenix uses fusion containers -- more or less the same, but with more horsepower (i.e. algorithms and iterators).

I read that part many times but I couldn't realize how to apply it to this case. I ended up calling

actor<LambdaExp>(at_c<0>(f_expr)) actor(at_c<1>(at_c<1>(f_expr)))(), //or at_c<1>(at_c<1>(f_expr)).val

seems to work so far (is there a make_actor?) I don't know if overall is the best solution.

Either works fine. Regards, -- Joel de Guzman http://www.boostpro.com http://spirit.sf.net http://www.facebook.com/djowel Meet me at BoostCon http://www.boostcon.com/home http://www.facebook.com/boostcon