[Olena-patches] olena-2.0-3-g1a8f843 Simplify and generalize the wrapping of lambdas in Milena functions.

* tests/data/transform-lambda.cc (first_arg_of, return_of): Remove traits. (fun_ptr): New trait. (to_fun): Adjust. Use `fun_ptr' instead of `first_arg_of' and `return_of' to create a more general pointer-to-function-based Milena functor. --- milena/ChangeLog | 11 ++++++++ milena/tests/data/transform-lambda.cc | 42 ++++++++------------------------ 2 files changed, 22 insertions(+), 31 deletions(-) diff --git a/milena/ChangeLog b/milena/ChangeLog index 745b3b6..a4f8dfb 100644 --- a/milena/ChangeLog +++ b/milena/ChangeLog @@ -1,5 +1,16 @@ 2012-05-22 Roland Levillain &lt;roland(a)lrde.epita.fr&gt; + Simplify and generalize the wrapping of lambdas in Milena functions. + + * tests/data/transform-lambda.cc (first_arg_of, return_of): + Remove traits. + (fun_ptr): New trait. + (to_fun): Adjust. Use `fun_ptr' instead of `first_arg_of' and + `return_of' to create a more general pointer-to-function-based + Milena functor. + +2012-05-22 Roland Levillain &lt;roland(a)lrde.epita.fr&gt; + Clean up tests/data/transform-lambda.cc. * tests/data/transform-lambda.cc (main): Remove a useless lambda. diff --git a/milena/tests/data/transform-lambda.cc b/milena/tests/data/transform-lambda.cc index d2cf485..1873b16 100644 --- a/milena/tests/data/transform-lambda.cc +++ b/milena/tests/data/transform-lambda.cc @@ -41,38 +41,20 @@ | Lambda traits. | `----------------*/ -// Metaprogramming traits for the deduction of return and argument -// types of lambda asbtractions. Inspired from +// Metaprogramming trait for the deduction of the pointer-to-function +// type equivalent to the type of a lambda asbtraction. Inspired from // http://stackoverflow.com/questions/6512019/can-we-get-the-type-of-a-lambda-… -/// Deduce the type of \p F's first argument. template <typename F> -struct first_arg_of +struct fun_ptr { - template <typename Ret, typename A, typename... Rest> - static A - helper(Ret (F::*)(A, Rest...)); + template <typename Ret, typename... Rest> + static auto + helper(Ret (F::*)(Rest...)) -> Ret(*)(Rest...); - template <typename Ret, typename A, typename... Rest> - static A - helper(Ret (F::*)(A, Rest...) const); - - typedef decltype( helper(&F::operator()) ) type; -}; - -/// Deduce the type of \p F's first argument. -/// -/// This traits works with lambdas, whereas std::result_of does not. -template <typename F> -struct return_of -{ - template <typename Ret, typename A, typename... Rest> - static Ret - helper(Ret (F::*)(A, Rest...)); - - template <typename Ret, typename A, typename... Rest> - static Ret - helper(Ret (F::*)(A, Rest...) const); + template <typename Ret, typename... Rest> + static auto + helper(Ret (F::*)(Rest...) const) -> Ret(*)(Rest...); typedef decltype( helper(&F::operator()) ) type; }; @@ -82,13 +64,11 @@ struct return_of | Conversion routine. | `---------------------*/ -/// Convert a lambda abstraction into a Milena function (functor). - template <typename F> auto -to_fun (F f) -> mln::fun::C< typename return_of<F>::type (*) (typename first_arg_of<F>::type) > +to_fun (F f) -> mln::fun::C< typename fun_ptr<F>::type > { - return mln::fun::C< typename return_of<F>::type (*) (typename first_arg_of<F>::type) > (f); + return mln::fun::C< typename fun_ptr<F>::type > (f); } -- 1.7.2.5