ceph/src/boost/boost/contract/check.hpp

   1
   2 #ifndef BOOST_CONTRACT_CHECK_HPP_
   3 #define BOOST_CONTRACT_CHECK_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 RAII object that checks contracts.
  12 */
  13
  14 #include <boost/contract/core/config.hpp>
  15 #include <boost/contract/core/check_macro.hpp>
  16 #include <boost/contract/core/specify.hpp>
  17 #include <boost/contract/core/exception.hpp> // For set_... (if always in code).
  18 #if !defined(BOOST_CONTRACT_NO_CONDITIONS) || \
  19         defined(BOOST_CONTRACT_STATIC_LINK)
  20     #include <boost/contract/detail/condition/cond_base.hpp>
  21     #include <boost/contract/detail/auto_ptr.hpp>
  22     #include <boost/contract/detail/debug.hpp>
  23 #endif
  24 #include <boost/contract/detail/check.hpp>
  25 #include <boost/config.hpp>
  26
  27 /* PRIVATE */
  28
  29 /** @cond */
  30
  31 #if !defined(BOOST_CONTRACT_NO_CONDITIONS) || \
  32         defined(BOOST_CONTRACT_STATIC_LINK)
  33     #define BOOST_CONTRACT_CHECK_CTOR_DEF_(contract_type) \
  34         : cond_(const_cast<contract_type&>(contract).cond_.release()) \
  35         { \
  36             BOOST_CONTRACT_DETAIL_DEBUG(cond_); \
  37             cond_->initialize(); \
  38         }
  39 #else
  40     #define BOOST_CONTRACT_CHECK_CTOR_DEF_(contract_type) {}
  41 #endif
  42
  43 /** @endcond */
  44
  45 /* CODE */
  46
  47 namespace boost { namespace contract {
  48
  49 /**
  50 RAII object that checks the contracts.
  51
  52 In general, when this object is constructed it checks class invariants at entry,
  53 preconditions, and makes old value copies at body.
  54 When it is destructed, it checks class invariants at exist, postconditions, and
  55 exception guarantees.
  56 This object enforces the following (see
  57 @RefSect{contract_programming_overview, Contract Programming Overview}):
  58
  59 @li Postconditions are checked only if the body does not throw an exception.
  60 @li Exceptions guarantees are checked only if the body throws an exception.
  61 @li Constructor entry never checks class invariants.
  62 @li Destructor exit checks class invariants only if the body throws an
  63 exception (even if destructors should usually not be programmed to throw
  64 exceptions in C++ and they are implicitly declared @c noexcept since C++11).
  65 @li Static invariants are always checked at entry and exit (and regardless of
  66 the body throwing exceptions or not).
  67
  68 When used this way, this object is constructed and initialized to the return
  69 value of one of the contract functions @RefFunc{boost::contract::function},
  70 @RefFunc{boost::contract::constructor}, @RefFunc{boost::contract::destructor},
  71 or @RefFunc{boost::contract::public_function}.
  72 In addition to that, this object can be constructed from a nullary functor when
  73 it is used to program implementation checks.
  74
  75 @see    @RefSect{tutorial, Tutorial},
  76         @RefSect{advanced.implementation_checks, Implementation Checks}
  77 */
  78 class check { // Copy ctor only (as move via ptr release).
  79 public:
  80     // NOTE: Unfortunately, Apple compilers define a `check(...)` macro that
  81     // clashes with the name of this class. In the following code,
  82     // BOOST_PREVENT_MACRO_SUBSTITUTION is used to workaround these name
  83     // clashes. In user code, `check c = ...` syntax is typically used also
  84     // avoiding clashes.
  85
  86     /**
  87     Construct this object for implementation checks.
  88
  89     This can be used to program checks within implementation code (body, etc.).
  90     This constructor is not declared @c explicit so initializations can use
  91     assignment syntax @c =.
  92
  93     @b Throws:  This can throw in case programmers specify contract failure
  94                 handlers that throw exceptions instead of terminating the
  95                 program (see
  96                 @RefSect{advanced.throw_on_failures__and__noexcept__,
  97                 Throw on Failure}).
  98
  99     @param f    Nullary functor that asserts implementation checks. @c f() will
 100                 be called as soon as this object is constructed at the point it
 101                 is declared within the implementation code (see
 102                 @RefSect{advanced.implementation_checks,
 103                 Implementation Checks}).
 104     */
 105     template<typename F> // Cannot check `if(f) ...` as f can be a lambda.
 106     // f must be a valid callable object (not null func ptr, empty ftor, etc.
 107     /* implicit */ check
 108     /** @cond **/ BOOST_PREVENT_MACRO_SUBSTITUTION /** @endcond */ (
 109             F const& f) {
 110         BOOST_CONTRACT_DETAIL_CHECK({ f(); })
 111     }
 112
 113     /**
 114     Construct this object copying it from the specified one.
 115
 116     This object will check the contract, the copied-from object will not (i.e.,
 117     contract check ownership is transferred from the copied object to the new
 118     object being created by this constructor).
 119
 120     @param other    Copied-from object.
 121     */
 122     check /** @cond **/ BOOST_PREVENT_MACRO_SUBSTITUTION /** @endcond */ (
 123             check const& other)
 124         #if !defined(BOOST_CONTRACT_NO_CONDITIONS) || \
 125                 defined(BOOST_CONTRACT_STATIC_LINK)
 126             // Copy ctor moves cond_ pointer to dest.
 127             : cond_(const_cast<check&>(other).cond_.release())
 128         #endif
 129     {}
 130
 131     /**
 132     Construct this object to check the specified contract.
 133
 134     This checks class invariants at entry (if those were specified for the given
 135     contract).
 136     This constructor is not declared @c explicit so initializations can use
 137     assignment syntax @c =.
 138
 139     @b Throws:  This can throw in case programmers specify contract failure
 140                 handlers that throw exceptions instead of terminating the
 141                 program (see
 142                 @RefSect{advanced.throw_on_failures__and__noexcept__,
 143                 Throw on Failure}).
 144
 145     @param contract Contract to be checked (usually the return value of
 146                     @RefFunc{boost::contract::function} or
 147                     @RefFunc{boost::contract::public_function}).
 148
 149     @tparam VirtualResult   Return type of the enclosing function declaring the
 150                             contract if that is either a virtual or an
 151                             overriding public function, otherwise this is always
 152                             @c void.
 153                             (Usually this template parameter is automatically
 154                             deduced by C++ and it does not need to be explicitly
 155                             specified by programmers.)
 156     */
 157     template<typename VirtualResult>
 158     /* implicit */ check
 159     /** @cond */ BOOST_PREVENT_MACRO_SUBSTITUTION /** @endcond */ (
 160         specify_precondition_old_postcondition_except<VirtualResult> const&
 161                 contract
 162     )
 163     #ifndef BOOST_CONTRACT_DETAIL_DOXYGEN
 164         BOOST_CONTRACT_CHECK_CTOR_DEF_(
 165                 specify_precondition_old_postcondition_except<VirtualResult>)
 166     #else
 167         ;
 168     #endif
 169
 170     /**
 171     Construct this object to check the specified contract.
 172
 173     This checks class invariants at entry and preconditions (if any of those
 174     were specified for the given contract).
 175     This constructor is not declared @c explicit so initializations can use
 176     assignment syntax @c =.
 177
 178     @b Throws:  This can throw in case programmers specify contract failure
 179                 handlers that throw exceptions instead of terminating the
 180                 program (see
 181                 @RefSect{advanced.throw_on_failures__and__noexcept__,
 182                 Throw on Failure}).
 183
 184     @param contract Contract to be checked (usually the return value of
 185                     @RefFunc{boost::contract::function},
 186                     @RefFunc{boost::contract::constructor},
 187                     @RefFunc{boost::contract::destructor}, or
 188                     @RefFunc{boost::contract::public_function}).
 189
 190     @tparam VirtualResult   Return type of the enclosing function declaring the
 191                             contract if that is either a virtual or an
 192                             overriding public function, otherwise this is always
 193                             @c void.
 194                             (Usually this template parameter is automatically
 195                             deduced by C++ and it does not need to be explicitly
 196                             specified by programmers.)
 197     */
 198     template<typename VirtualResult>
 199     /* implicit */ check
 200     /** @cond */ BOOST_PREVENT_MACRO_SUBSTITUTION /** @endcond */ (
 201             specify_old_postcondition_except<VirtualResult> const& contract)
 202     #ifndef BOOST_CONTRACT_DETAIL_DOXYGEN
 203         BOOST_CONTRACT_CHECK_CTOR_DEF_(
 204                 specify_old_postcondition_except<VirtualResult>)
 205     #else
 206         ;
 207     #endif
 208
 209     /**
 210     Construct this object to check the specified contract.
 211
 212     This checks class invariants at entry and preconditions then it makes old
 213     value copies at body (if any of those were specified for the given
 214     contract).
 215     This constructor is not declared @c explicit so initializations can use
 216     assignment syntax @c =.
 217
 218     @b Throws:  This can throw in case programmers specify contract failure
 219                 handlers that throw exceptions instead of terminating te
 220                 program (see
 221                 @RefSect{advanced.throw_on_failures__and__noexcept__,
 222                 Throw on Failure}).
 223
 224     @param contract Contract to be checked (usually the return value of
 225                     @RefFunc{boost::contract::function},
 226                     @RefFunc{boost::contract::constructor},
 227                     @RefFunc{boost::contract::destructor}, or
 228                     @RefFunc{boost::contract::public_function}).
 229
 230     @tparam VirtualResult   Return type of the enclosing function declaring the
 231                             contract if that is either a virtual or an
 232                             overriding public function, otherwise this is always
 233                             @c void.
 234                             (Usually this template parameter is automatically
 235                             deduced by C++ and it does not need to be explicitly
 236                             specified by programmers.)
 237     */
 238     template<typename VirtualResult>
 239     /* implicit */ check
 240     /** @cond */ BOOST_PREVENT_MACRO_SUBSTITUTION /** @endcond */ (
 241             specify_postcondition_except<VirtualResult> const& contract)
 242     #ifndef BOOST_CONTRACT_DETAIL_DOXYGEN
 243         BOOST_CONTRACT_CHECK_CTOR_DEF_(
 244                 specify_postcondition_except<VirtualResult>)
 245     #else
 246         ;
 247     #endif
 248
 249     /**
 250     Construct this object to check the specified contract.
 251
 252     This checks class invariants at entry and preconditions then it makes old
 253     value copies at body, plus the destructor of this object will also check
 254     postconditions in this case (if any of those were specified for the given
 255     contract).
 256     This constructor is not declared @c explicit so initializations can use
 257     assignment syntax @c =.
 258
 259     @b Throws:  This can throw in case programmers specify contract failure
 260                 handlers that throw exceptions instead of terminating the
 261                 program (see
 262                 @RefSect{advanced.throw_on_failures__and__noexcept__,
 263                 Throw on Failure}).
 264
 265     @param contract Contract to be checked (usually the return value of
 266                     @RefFunc{boost::contract::function},
 267                     @RefFunc{boost::contract::constructor},
 268                     @RefFunc{boost::contract::destructor}, or
 269                     @RefFunc{boost::contract::public_function}).
 270
 271     @tparam VirtualResult   Return type of the enclosing function declaring the
 272                             contract if that is either a virtual or an
 273                             overriding public function, otherwise this is always
 274                             @c void.
 275                             (Usually this template parameter is automatically
 276                             deduced by C++ and it does not need to be explicitly
 277                             specified by programmers.)
 278     */
 279     /* implicit */ check
 280     /** @cond */ BOOST_PREVENT_MACRO_SUBSTITUTION /** @endcond */ (
 281             specify_except const& contract)
 282     #ifndef BOOST_CONTRACT_DETAIL_DOXYGEN
 283         BOOST_CONTRACT_CHECK_CTOR_DEF_(specify_except)
 284     #else
 285         ;
 286     #endif
 287
 288     /**
 289     Construct this object to check the specified contract.
 290
 291     This checks class invariants at entry and preconditions then it makes old
 292     value copies at body, plus the destructor of this object will also check
 293     postconditions and exception guarantees in this case (if any of those were
 294     specified for the given contract).
 295     This constructor is not declared @c explicit so initializations can use
 296     assignment syntax @c =.
 297
 298     @b Throws:  This can throw in case programmers specify contract failure
 299                 handlers that throw exceptions instead of terminating the
 300                 program (see
 301                 @RefSect{advanced.throw_on_failures__and__noexcept__,
 302                 Throw on Failure}).
 303
 304     @param contract Contract to be checked (usually the return value of
 305                     @RefFunc{boost::contract::function},
 306                     @RefFunc{boost::contract::constructor},
 307                     @RefFunc{boost::contract::destructor}, or
 308                     @RefFunc{boost::contract::public_function}).
 309
 310     @tparam VirtualResult   Return type of the enclosing function declaring the
 311                             contract if that is either a virtual or an
 312                             overriding public function, otherwise this is always
 313                             @c void.
 314                             (Usually this template parameter is automatically
 315                             deduced by C++ and it does not need to be explicitly
 316                             specified by programmers.)
 317     */
 318     /* implicit */ check
 319     /** @cond */ BOOST_PREVENT_MACRO_SUBSTITUTION /** @endcond */ (
 320             specify_nothing const& contract)
 321     #ifndef BOOST_CONTRACT_DETAIL_DOXYGEN
 322         BOOST_CONTRACT_CHECK_CTOR_DEF_(specify_nothing)
 323     #else
 324         ;
 325     #endif
 326
 327     /**
 328     Destruct this object.
 329
 330     This checks class invariants at exit and either postconditions when the
 331     enclosing function body did not throw an exception, or exception guarantees
 332     when the function body threw an exception (if class invariants,
 333     postconditions, and exception guarantees respectively were specified for the
 334     enclosing class and the contract parameter given when constructing this
 335     object).
 336
 337     @b Throws:  This can throw in case programmers specify contract failure
 338                 handlers that throw exceptions instead of terminating the
 339                 program (see
 340                 @RefSect{advanced.throw_on_failures__and__noexcept__,
 341                 Throw on Failure}).
 342                 (This is declared @c noexcept(false) since C++11.)
 343     */
 344     ~check /** @cond */ BOOST_PREVENT_MACRO_SUBSTITUTION /** @endcond */ ()
 345         BOOST_NOEXCEPT_IF(false) /* allow auto_ptr dtor to throw */
 346     {}
 347
 348 /** @cond */
 349 private:
 350     check& operator=(check const&); // Cannot copy outside of `check c = ...`.
 351
 352     #if !defined(BOOST_CONTRACT_NO_CONDITIONS) || \
 353             defined(BOOST_CONTRACT_STATIC_LINK)
 354         boost::contract::detail::auto_ptr<boost::contract::detail::cond_base>
 355                 cond_;
 356     #endif
 357 /** @endcond */
 358 };
 359
 360 } } // namespace
 361
 362 #endif // #include guard
 363