boost/boost/type_traits/is_function.hpp

   1
   2 //  Copyright 2000 John Maddock (john@johnmaddock.co.uk)
   3 //  Copyright 2002 Aleksey Gurtovoy (agurtovoy@meta-comm.com)
   4 //
   5 //  Use, modification and distribution are subject to the Boost Software License,
   6 //  Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   7 //  http://www.boost.org/LICENSE_1_0.txt).
   8 //
   9 //  See http://www.boost.org/libs/type_traits for most recent version including documentation.
  10
  11 #ifndef BOOST_TT_IS_FUNCTION_HPP_INCLUDED
  12 #define BOOST_TT_IS_FUNCTION_HPP_INCLUDED
  13
  14 #include "boost/type_traits/is_reference.hpp"
  15 #include "boost/type_traits/detail/false_result.hpp"
  16 #include "boost/config.hpp"
  17
  18 #if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) && !defined(BOOST_TT_TEST_MS_FUNC_SIGS)
  19 #   include "boost/type_traits/detail/is_function_ptr_helper.hpp"
  20 #else
  21 #   include "boost/type_traits/detail/is_function_ptr_tester.hpp"
  22 #   include "boost/type_traits/detail/yes_no_type.hpp"
  23 #endif
  24
  25 // should be the last #include
  26 #include "boost/type_traits/detail/bool_trait_def.hpp"
  27
  28 // is a type a function?
  29 // Please note that this implementation is unnecessarily complex:
  30 // we could just use !is_convertible<T*, const volatile void*>::value,
  31 // except that some compilers erroneously allow conversions from
  32 // function pointers to void*.
  33
  34 namespace boost {
  35 namespace detail {
  36
  37 #if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) && !defined(BOOST_TT_TEST_MS_FUNC_SIGS)
  38 template<bool is_ref = true>
  39 struct is_function_chooser
  40     : ::boost::type_traits::false_result
  41 {
  42 };
  43
  44 template <>
  45 struct is_function_chooser<false>
  46 {
  47     template< typename T > struct result_
  48         : ::boost::type_traits::is_function_ptr_helper<T*>
  49     {
  50     };
  51 };
  52
  53 template <typename T>
  54 struct is_function_impl
  55     : is_function_chooser< ::boost::is_reference<T>::value >
  56         ::BOOST_NESTED_TEMPLATE result_<T>
  57 {
  58 };
  59
  60 #else
  61
  62 template <typename T>
  63 struct is_function_impl
  64 {
  65     static T* t;
  66     BOOST_STATIC_CONSTANT(
  67         bool, value = sizeof(::boost::type_traits::is_function_ptr_tester(t))
  68         == sizeof(::boost::type_traits::yes_type)
  69         );
  70 };
  71
  72 #if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
  73 template <typename T>
  74 struct is_function_impl<T&> : public false_type
  75 {};
  76 #endif
  77
  78 #endif
  79
  80 } // namespace detail
  81
  82 BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_function,T,::boost::detail::is_function_impl<T>::value)
  83
  84 } // namespace boost
  85
  86 #include "boost/type_traits/detail/bool_trait_undef.hpp"
  87
  88 #endif // BOOST_TT_IS_FUNCTION_HPP_INCLUDED