boost/contract/override.hpp

   1
   2 #ifndef BOOST_CONTRACT_OVERRIDE_HPP_
   3 #define BOOST_CONTRACT_OVERRIDE_HPP_
   4
   5 // Copyright (C) 2008-2018 Lorenzo Caminiti
   6 // Distributed under the Boost Software License, Version 1.0 (see accompanying
   7 // file LICENSE_1_0.txt or a copy at http://www.boost.org/LICENSE_1_0.txt).
   8 // See: http://www.boost.org/doc/libs/release/libs/contract/doc/html/index.html
   9
  10 /** @file
  11 Handle public function overrides (for subcontracting).
  12 */
  13
  14 // IMPORTANT: Included by contract_macro.hpp so must #if-guard all its includes.
  15 #include <boost/contract/core/config.hpp>
  16 #include <boost/preprocessor/cat.hpp>
  17 #include <boost/preprocessor/config/config.hpp>
  18
  19 #ifdef BOOST_CONTRACT_DETAIL_DOXYGEN
  20     /**
  21     Declare an override type trait with an arbitrary name.
  22
  23     Declare the override type trait named @c type_name to pass as an explicit
  24     template parameter to @RefFunc{boost::contract::public_function} for public
  25     function overrides.
  26
  27     @see @RefSect{advanced.named_overrides, Named Overrides}
  28
  29     @param type_name    Name of the override type trait this macro will declare.
  30                         (This is not a variadic macro parameter but it should
  31                         never contain commas because it is an identifier.)
  32     @param func_name    Function name of the public function override.
  33                         This macro is called just once even if the function name
  34                         is overloaded (the same override type trait is used for
  35                         all overloaded functions with the same name, see
  36                         @RefSect{advanced.function_overloads,
  37                         Function Overloads}).
  38                         (This is not a variadic macro parameter but it should
  39                         never contain commas because it is an identifier.)
  40     */
  41     #define BOOST_CONTRACT_NAMED_OVERRIDE(type_name, func_name)
  42 #elif !defined(BOOST_CONTRACT_NO_PUBLIC_FUNCTIONS)
  43     #include <boost/contract/core/virtual.hpp>
  44     #include <boost/contract/detail/type_traits/mirror.hpp>
  45     #include <boost/contract/detail/tvariadic.hpp>
  46     #include <boost/contract/detail/none.hpp>
  47     #include <boost/contract/detail/name.hpp>
  48
  49     /* PRIVATE */
  50
  51     #define BOOST_CONTRACT_OVERRIDE_CALL_BASE_(z, arity, arity_compl, \
  52             func_name) \
  53         template< \
  54             class BOOST_CONTRACT_DETAIL_NAME1(B), \
  55             class BOOST_CONTRACT_DETAIL_NAME1(C) \
  56             BOOST_CONTRACT_DETAIL_TVARIADIC_COMMA(arity) \
  57             BOOST_CONTRACT_DETAIL_TVARIADIC_TPARAMS_Z(z, arity, \
  58                     BOOST_CONTRACT_DETAIL_NAME1(Args)) \
  59         > \
  60         static void BOOST_CONTRACT_DETAIL_NAME1(call_base)( \
  61             boost::contract::virtual_* BOOST_CONTRACT_DETAIL_NAME1(v), \
  62             BOOST_CONTRACT_DETAIL_NAME1(C)* BOOST_CONTRACT_DETAIL_NAME1(obj) \
  63             BOOST_CONTRACT_DETAIL_TVARIADIC_COMMA(arity) \
  64             BOOST_CONTRACT_DETAIL_TVARIADIC_FPARAMS_Z(z, arity, \
  65                 BOOST_CONTRACT_DETAIL_NAME1(Args), \
  66                 &, \
  67                 BOOST_CONTRACT_DETAIL_NAME1(args) \
  68             ) \
  69             BOOST_CONTRACT_DETAIL_NO_TVARIADIC_COMMA(arity_compl) \
  70             BOOST_CONTRACT_DETAIL_NO_TVARIADIC_ENUM_Z(z, arity_compl, \
  71                     boost::contract::detail::none&) \
  72         ) { \
  73             BOOST_CONTRACT_DETAIL_NAME1(obj)-> \
  74             BOOST_CONTRACT_DETAIL_NAME1(B)::func_name( \
  75                 BOOST_CONTRACT_DETAIL_TVARIADIC_ARGS_Z(z, arity, \
  76                         BOOST_CONTRACT_DETAIL_NAME1(args)) \
  77                 BOOST_CONTRACT_DETAIL_TVARIADIC_COMMA(arity) \
  78                 BOOST_CONTRACT_DETAIL_NAME1(v) \
  79             ); \
  80         }
  81
  82     #if BOOST_CONTRACT_DETAIL_TVARIADIC
  83         #define BOOST_CONTRACT_OVERRIDE_CALL_BASE_DECL_(func_name) \
  84             BOOST_CONTRACT_OVERRIDE_CALL_BASE_(1, ~, ~, func_name)
  85     #else
  86         #include <boost/preprocessor/repetition/repeat.hpp>
  87         #include <boost/preprocessor/arithmetic/inc.hpp>
  88         #include <boost/preprocessor/arithmetic/sub.hpp>
  89
  90         #define BOOST_CONTRACT_OVERRIDE_CALL_BASE_DECL_(func_name) \
  91             BOOST_PP_REPEAT(BOOST_PP_INC(BOOST_CONTRACT_MAX_ARGS), \
  92                     BOOST_CONTRACT_OVERRIDE_CALL_BASE_ARITY_, func_name) \
  93
  94         #define BOOST_CONTRACT_OVERRIDE_CALL_BASE_ARITY_(z, arity, func_name) \
  95             BOOST_CONTRACT_OVERRIDE_CALL_BASE_(z, arity, \
  96                     BOOST_PP_SUB(BOOST_CONTRACT_MAX_ARGS, arity), func_name)
  97     #endif
  98
  99     /* PUBLIC */
 100
 101     #define BOOST_CONTRACT_NAMED_OVERRIDE(type_name, func_name) \
 102         struct type_name { \
 103             BOOST_CONTRACT_DETAIL_MIRROR_HAS_MEMBER_FUNCTION( \
 104                 BOOST_CONTRACT_DETAIL_NAME1(has_member_function), \
 105                 func_name \
 106             ) \
 107             BOOST_CONTRACT_OVERRIDE_CALL_BASE_DECL_(func_name) \
 108         };
 109 #else
 110     #define BOOST_CONTRACT_NAMED_OVERRIDE(type_name, func_name) \
 111             struct type_name {}; /* empty (not used), just to compile */
 112 #endif
 113
 114 /* PUBLIC */
 115
 116 /**
 117 Declare an override type trait named <c>override_<i>func_name</i></c>.
 118
 119 Declare the override type trait named <c>override_<i>func_name</i></c> to pass
 120 as an explicit template parameter to @RefFunc{boost::contract::public_function}
 121 for public function overrides.
 122 Use @RefMacro{BOOST_CONTRACT_NAMED_OVERRIDE} to generate an override type trait
 123 with a name different than <c>override_<i>func_name</i></c> (usually not
 124 needed).
 125
 126 @see    @RefSect{tutorial.public_function_overrides__subcontracting_,
 127         Public Function Overrides}
 128
 129 @param func_name    Function name of the public function override.
 130                     This macro is called just once even if the function name is
 131                     overloaded (the same override type trait is used for all
 132                     overloaded functions with the same name, see
 133                     @RefSect{advanced.function_overloads, Function Overloads}).
 134                     (This is not a variadic macro parameter but it should never
 135                     contain any comma because it is an identifier.)
 136 */
 137 #define BOOST_CONTRACT_OVERRIDE(func_name) \
 138     BOOST_CONTRACT_NAMED_OVERRIDE(BOOST_PP_CAT(override_, func_name), func_name)
 139
 140 #ifdef BOOST_CONTRACT_DETAIL_DOXYGEN
 141     /**
 142     Declare multiple override type traits at once naming them
 143     <c>override_...</c> (for convenience).
 144
 145     This variadic macro is provided for convenience as
 146     <c>BOOST_CONTRACT_OVERRIDES(f_1, f_2, ..., f_n)</c> expands to code
 147     equivalent to:
 148
 149     @code
 150     BOOST_CONTRACT_OVERRIDE(f_1)
 151     BOOST_CONTRACT_OVERRIDE(f_2)
 152     ...
 153     BOOST_CONTRACT_OVERRIDE(f_n)
 154     @endcode
 155
 156     On compilers that do not support variadic macros,
 157     the override type traits can be equivalently programmed one-by-one calling
 158     @RefMacro{BOOST_CONTRACT_OVERRIDE} for each function name as shown above.
 159
 160     @see    @RefSect{tutorial.public_function_overrides__subcontracting_,
 161             Public Function Overrides}
 162
 163     @param ...  A comma separated list of one or more function names of public
 164                 function overrides.
 165                 (Each function name should never contain commas because it is an
 166                 identifier.)
 167     */
 168     #define BOOST_CONTRACT_OVERRIDES(...)
 169 #elif BOOST_PP_VARIADICS
 170     #include <boost/preprocessor/seq/for_each.hpp>
 171     #include <boost/preprocessor/variadic/to_seq.hpp>
 172
 173     /* PRIVATE */
 174
 175     #define BOOST_CONTRACT_OVERRIDES_SEQ_(r, unused, func_name) \
 176         BOOST_CONTRACT_OVERRIDE(func_name)
 177
 178     /* PUBLIC */
 179
 180     #define BOOST_CONTRACT_OVERRIDES(...) \
 181         BOOST_PP_SEQ_FOR_EACH(BOOST_CONTRACT_OVERRIDES_SEQ_, ~, \
 182                 BOOST_PP_VARIADIC_TO_SEQ(__VA_ARGS__))
 183 #else
 184     #define BOOST_CONTRACT_OVERRIDES \
 185 BOOST_CONTRACT_ERROR_macro_OVERRIDES_requires_variadic_macros_otherwise_manually_repeat_OVERRIDE_macro
 186 #endif
 187
 188 #endif // #include guard
 189