ceph/src/boost/libs/lambda/include/boost/lambda/detail/lambda_functors.hpp

   1 // Boost Lambda Library -  lambda_functors.hpp -------------------------------
   2
   3 // Copyright (C) 1999, 2000 Jaakko Jarvi (jaakko.jarvi@cs.utu.fi)
   4 //
   5 // Distributed under the Boost Software License, Version 1.0. (See
   6 // accompanying file LICENSE_1_0.txt or copy at
   7 // http://www.boost.org/LICENSE_1_0.txt)
   8 //
   9 // For more information, see http://www.boost.org
  10
  11 // ------------------------------------------------
  12
  13 #ifndef BOOST_LAMBDA_LAMBDA_FUNCTORS_HPP
  14 #define BOOST_LAMBDA_LAMBDA_FUNCTORS_HPP
  15
  16 #include <boost/config.hpp>
  17 #include <boost/detail/workaround.hpp>
  18 #include <boost/utility/result_of.hpp>
  19
  20 #if BOOST_WORKAROUND(BOOST_MSVC, == 1310)
  21
  22 #include <boost/mpl/or.hpp>
  23 #include <boost/utility/enable_if.hpp>
  24 #include <boost/type_traits/is_array.hpp>
  25
  26 #define BOOST_LAMBDA_DISABLE_IF_ARRAY1(A1, R1)\
  27   typename lazy_disable_if<is_array<A1>, typename R1 >::type
  28 #define BOOST_LAMBDA_DISABLE_IF_ARRAY2(A1, A2, R1, R2) \
  29   typename lazy_disable_if<mpl::or_<is_array<A1>, is_array<A2> >, typename R1, R2 >::type
  30 #define BOOST_LAMBDA_DISABLE_IF_ARRAY3(A1, A2, A3, R1, R2, R3) \
  31   typename lazy_disable_if<mpl::or_<is_array<A1>, is_array<A2>, is_array<A3> >, typename R1, R2, R3 >::type
  32
  33 #else
  34
  35 #define BOOST_LAMBDA_DISABLE_IF_ARRAY1(A1, R1) typename R1::type
  36 #define BOOST_LAMBDA_DISABLE_IF_ARRAY2(A1, A2, R1, R2) typename R1, R2::type
  37 #define BOOST_LAMBDA_DISABLE_IF_ARRAY3(A1, A2, A3, R1, R2, R3) typename R1, R2, R3::type
  38
  39 #endif
  40
  41 namespace boost {
  42 namespace lambda {
  43
  44 // -- lambda_functor --------------------------------------------
  45 // --------------------------------------------------------------
  46
  47 //inline const null_type const_null_type() { return null_type(); }
  48
  49 namespace detail {
  50 namespace {
  51
  52   static const null_type constant_null_type = null_type();
  53
  54 } // unnamed
  55 } // detail
  56
  57 class unused {};
  58
  59 #define cnull_type() detail::constant_null_type
  60
  61 // -- free variables types --------------------------------------------------
  62
  63   // helper to work around the case where the nullary return type deduction
  64   // is always performed, even though the functor is not nullary
  65 namespace detail {
  66   template<int N, class Tuple> struct get_element_or_null_type {
  67     typedef typename
  68       detail::tuple_element_as_reference<N, Tuple>::type type;
  69   };
  70   template<int N> struct get_element_or_null_type<N, null_type> {
  71     typedef null_type type;
  72   };
  73 }
  74
  75 template <int I> struct placeholder;
  76
  77 template<> struct placeholder<FIRST> {
  78
  79   template<class SigArgs> struct sig {
  80     typedef typename detail::get_element_or_null_type<0, SigArgs>::type type;
  81   };
  82
  83   template<class RET, CALL_TEMPLATE_ARGS>
  84   RET call(CALL_FORMAL_ARGS) const {
  85     BOOST_STATIC_ASSERT(boost::is_reference<RET>::value);
  86     CALL_USE_ARGS; // does nothing, prevents warnings for unused args
  87     return a;
  88   }
  89 };
  90
  91 template<> struct placeholder<SECOND> {
  92
  93   template<class SigArgs> struct sig {
  94     typedef typename detail::get_element_or_null_type<1, SigArgs>::type type;
  95   };
  96
  97   template<class RET, CALL_TEMPLATE_ARGS>
  98   RET call(CALL_FORMAL_ARGS) const { CALL_USE_ARGS; return b; }
  99 };
 100
 101 template<> struct placeholder<THIRD> {
 102
 103   template<class SigArgs> struct sig {
 104     typedef typename detail::get_element_or_null_type<2, SigArgs>::type type;
 105   };
 106
 107   template<class RET, CALL_TEMPLATE_ARGS>
 108   RET call(CALL_FORMAL_ARGS) const { CALL_USE_ARGS; return c; }
 109 };
 110
 111 template<> struct placeholder<EXCEPTION> {
 112
 113   template<class SigArgs> struct sig {
 114     typedef typename detail::get_element_or_null_type<3, SigArgs>::type type;
 115   };
 116
 117   template<class RET, CALL_TEMPLATE_ARGS>
 118   RET call(CALL_FORMAL_ARGS) const { CALL_USE_ARGS; return env; }
 119 };
 120
 121 typedef const lambda_functor<placeholder<FIRST> >  placeholder1_type;
 122 typedef const lambda_functor<placeholder<SECOND> > placeholder2_type;
 123 typedef const lambda_functor<placeholder<THIRD> >  placeholder3_type;
 124
 125
 126 ///////////////////////////////////////////////////////////////////////////////
 127
 128
 129 // free variables are lambda_functors. This is to allow uniform handling with
 130 // other lambda_functors.
 131 // -------------------------------------------------------------------
 132
 133 #if BOOST_WORKAROUND(BOOST_MSVC, >= 1400)
 134 #pragma warning(push)
 135 #pragma warning(disable:4512) //assignment operator could not be generated
 136 #endif
 137
 138 // -- lambda_functor NONE ------------------------------------------------
 139 template <class T>
 140 class lambda_functor : public T
 141 {
 142
 143 BOOST_STATIC_CONSTANT(int, arity_bits = get_arity<T>::value);
 144
 145 public:
 146   typedef T inherited;
 147
 148   lambda_functor() {}
 149   lambda_functor(const lambda_functor& l) : inherited(l) {}
 150
 151   lambda_functor(const T& t) : inherited(t) {}
 152
 153   template <class SigArgs> struct sig {
 154     typedef typename inherited::template
 155       sig<typename SigArgs::tail_type>::type type;
 156   };
 157
 158   // Note that this return type deduction template is instantiated, even
 159   // if the nullary
 160   // operator() is not called at all. One must make sure that it does not fail.
 161   typedef typename
 162     inherited::template sig<null_type>::type
 163       nullary_return_type;
 164
 165   // Support for boost::result_of.
 166   template <class Sig> struct result;
 167   template <class F>
 168   struct result<F()> {
 169     typedef nullary_return_type type;
 170   };
 171   template <class F, class A>
 172   struct result<F(A)> {
 173     typedef typename sig<tuple<F, A> >::type type;
 174   };
 175   template <class F, class A, class B>
 176   struct result<F(A, B)> {
 177     typedef typename sig<tuple<F, A, B> >::type type;
 178   };
 179   template <class F, class A, class B, class C>
 180   struct result<F(A, B, C)> {
 181     typedef typename sig<tuple<F, A, B, C> >::type type;
 182   };
 183
 184   nullary_return_type operator()() const {
 185     return inherited::template
 186       call<nullary_return_type>
 187         (cnull_type(), cnull_type(), cnull_type(), cnull_type());
 188   }
 189
 190   template<class A>
 191   typename inherited::template sig<tuple<A&> >::type
 192   operator()(A& a) const {
 193     return inherited::template call<
 194       typename inherited::template sig<tuple<A&> >::type
 195     >(a, cnull_type(), cnull_type(), cnull_type());
 196   }
 197
 198   template<class A>
 199   BOOST_LAMBDA_DISABLE_IF_ARRAY1(A, inherited::template sig<tuple<A const&> >)
 200   operator()(A const& a) const {
 201     return inherited::template call<
 202       typename inherited::template sig<tuple<A const&> >::type
 203     >(a, cnull_type(), cnull_type(), cnull_type());
 204   }
 205
 206   template<class A, class B>
 207   typename inherited::template sig<tuple<A&, B&> >::type
 208   operator()(A& a, B& b) const {
 209     return inherited::template call<
 210       typename inherited::template sig<tuple<A&, B&> >::type
 211     >(a, b, cnull_type(), cnull_type());
 212   }
 213
 214   template<class A, class B>
 215   BOOST_LAMBDA_DISABLE_IF_ARRAY2(A, B, inherited::template sig<tuple<A const&, B&> >)
 216   operator()(A const& a, B& b) const {
 217     return inherited::template call<
 218       typename inherited::template sig<tuple<A const&, B&> >::type
 219     >(a, b, cnull_type(), cnull_type());
 220   }
 221
 222   template<class A, class B>
 223   BOOST_LAMBDA_DISABLE_IF_ARRAY2(A, B, inherited::template sig<tuple<A&, B const&> >)
 224   operator()(A& a, B const& b) const {
 225     return inherited::template call<
 226       typename inherited::template sig<tuple<A&, B const&> >::type
 227     >(a, b, cnull_type(), cnull_type());
 228   }
 229
 230   template<class A, class B>
 231   BOOST_LAMBDA_DISABLE_IF_ARRAY2(A, B, inherited::template sig<tuple<A const&, B const&> >)
 232   operator()(A const& a, B const& b) const {
 233     return inherited::template call<
 234       typename inherited::template sig<tuple<A const&, B const&> >::type
 235     >(a, b, cnull_type(), cnull_type());
 236   }
 237
 238   template<class A, class B, class C>
 239   typename inherited::template sig<tuple<A&, B&, C&> >::type
 240   operator()(A& a, B& b, C& c) const
 241   {
 242     return inherited::template call<
 243       typename inherited::template sig<tuple<A&, B&, C&> >::type
 244     >(a, b, c, cnull_type());
 245   }
 246
 247   template<class A, class B, class C>
 248   BOOST_LAMBDA_DISABLE_IF_ARRAY3(A, B, C, inherited::template sig<tuple<A const&, B const&, C const&> >)
 249   operator()(A const& a, B const& b, C const& c) const
 250   {
 251     return inherited::template call<
 252       typename inherited::template sig<tuple<A const&, B const&, C const&> >::type
 253     >(a, b, c, cnull_type());
 254   }
 255
 256   // for internal calls with env
 257   template<CALL_TEMPLATE_ARGS>
 258   typename inherited::template sig<tuple<CALL_REFERENCE_TYPES> >::type
 259   internal_call(CALL_FORMAL_ARGS) const {
 260      return inherited::template
 261        call<typename inherited::template
 262          sig<tuple<CALL_REFERENCE_TYPES> >::type>(CALL_ACTUAL_ARGS);
 263   }
 264
 265   template<class A>
 266   const lambda_functor<lambda_functor_base<
 267                   other_action<assignment_action>,
 268                   boost::tuple<lambda_functor,
 269                   typename const_copy_argument <const A>::type> > >
 270   operator=(const A& a) const {
 271     return lambda_functor_base<
 272                   other_action<assignment_action>,
 273                   boost::tuple<lambda_functor,
 274                   typename const_copy_argument <const A>::type> >
 275      (  boost::tuple<lambda_functor,
 276              typename const_copy_argument <const A>::type>(*this, a) );
 277   }
 278
 279   template<class A>
 280   const lambda_functor<lambda_functor_base<
 281                   other_action<subscript_action>,
 282                   boost::tuple<lambda_functor,
 283                         typename const_copy_argument <const A>::type> > >
 284   operator[](const A& a) const {
 285     return lambda_functor_base<
 286                   other_action<subscript_action>,
 287                   boost::tuple<lambda_functor,
 288                         typename const_copy_argument <const A>::type> >
 289      ( boost::tuple<lambda_functor,
 290              typename const_copy_argument <const A>::type>(*this, a ) );
 291   }
 292 };
 293
 294 #if BOOST_WORKAROUND(BOOST_MSVC, >= 1400)
 295 #pragma warning(pop)
 296 #endif
 297
 298 } // namespace lambda
 299 } // namespace boost
 300
 301 namespace boost {
 302
 303 #if !defined(BOOST_RESULT_OF_USE_DECLTYPE) || defined(BOOST_NO_CXX11_DECLTYPE)
 304
 305 template<class T>
 306 struct result_of<boost::lambda::lambda_functor<T>()>
 307 {
 308     typedef typename boost::lambda::lambda_functor<T>::nullary_return_type type;
 309 };
 310
 311 template<class T>
 312 struct result_of<const boost::lambda::lambda_functor<T>()>
 313 {
 314     typedef typename boost::lambda::lambda_functor<T>::nullary_return_type type;
 315 };
 316
 317 #endif
 318
 319 template<class T>
 320 struct tr1_result_of<boost::lambda::lambda_functor<T>()>
 321 {
 322     typedef typename boost::lambda::lambda_functor<T>::nullary_return_type type;
 323 };
 324
 325 template<class T>
 326 struct tr1_result_of<const boost::lambda::lambda_functor<T>()>
 327 {
 328     typedef typename boost::lambda::lambda_functor<T>::nullary_return_type type;
 329 };
 330
 331 }
 332
 333 // is_placeholder
 334
 335 #include <boost/is_placeholder.hpp>
 336
 337 namespace boost
 338 {
 339
 340 template<> struct is_placeholder< lambda::lambda_functor< lambda::placeholder<lambda::FIRST> > >
 341 {
 342     enum _vt { value = 1 };
 343 };
 344
 345 template<> struct is_placeholder< lambda::lambda_functor< lambda::placeholder<lambda::SECOND> > >
 346 {
 347     enum _vt { value = 2 };
 348 };
 349
 350 template<> struct is_placeholder< lambda::lambda_functor< lambda::placeholder<lambda::THIRD> > >
 351 {
 352     enum _vt { value = 3 };
 353 };
 354
 355 } // namespace boost
 356
 357 #endif