src/ceph/src/common/function_signature.h

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3 /*
   4  * Copied from:
   5  * https://github.com/exclipy/inline_variant_visitor/blob/master/function_signature.hpp
   6  * which apparently copied it from
   7  * http://stackoverflow.com/questions/4771417/how-to-get-the-signature-of-a-c-bind-expression
   8  */
   9
  10 #ifndef FUNCTION_SIGNATURE_H
  11 #define FUNCTION_SIGNATURE_H
  12
  13 #include <boost/mpl/pop_front.hpp>
  14 #include <boost/mpl/push_front.hpp>
  15 #include <boost/function_types/function_type.hpp>
  16 #include <boost/function_types/result_type.hpp>
  17 #include <boost/function_types/parameter_types.hpp>
  18
  19 template <typename F>
  20 struct signature_of_member
  21 {
  22     typedef typename boost::function_types::result_type<F>::type result_type;
  23     typedef typename boost::function_types::parameter_types<F>::type parameter_types;
  24     typedef typename boost::mpl::pop_front<parameter_types>::type base;
  25     typedef typename boost::mpl::push_front<base, result_type>::type L;
  26     typedef typename boost::function_types::function_type<L>::type type;
  27 };
  28
  29 template <typename F, bool is_class>
  30 struct signature_of_impl
  31 {
  32     typedef typename boost::function_types::function_type<F>::type type;
  33 };
  34
  35 template <typename F>
  36 struct signature_of_impl<F, true>
  37 {
  38     typedef typename signature_of_member<decltype(&F::operator())>::type type;
  39 };
  40
  41 template <typename F>
  42 struct signature_of
  43 {
  44     typedef typename signature_of_impl<F, boost::is_class<F>::value>::type type;
  45 };
  46
  47 #endif