text: //  (C) Copyright John Maddock 2000.
  //  Use, modification and distribution are subject to the 
  //  Boost Software License, Version 1.0. (See accompanying file 
  //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  
  //  See http://www.boost.org/libs/static_assert for documentation.
  
  /*
   Revision history:
     02 August 2000
        Initial version.
  */
  
  #ifndef BOOST_STATIC_ASSERT_HPP
  #define BOOST_STATIC_ASSERT_HPP
  
  #include <boost/config.hpp>
  #include <boost/detail/workaround.hpp>
  
  #ifdef __BORLANDC__
  //
  // workaround for buggy integral-constant expression support:
  #define BOOST_BUGGY_INTEGRAL_CONSTANT_EXPRESSIONS
  #endif
  
  #if defined(__GNUC__) && (__GNUC__ == 3) && ((__GNUC_MINOR__ == 3) || (__GNUC_MINOR__ == 4))
  // gcc 3.3 and 3.4 don't produce good error messages with the default version:
  #  define BOOST_SA_GCC_WORKAROUND
  #endif
  
  //
  // If the compiler issues warnings about old C style casts,
  // then enable this:
  //
  #if defined(__GNUC__) && ((__GNUC__ > 3) || ((__GNUC__ == 3) && (__GNUC_MINOR__ >= 4)))
  #  define BOOST_STATIC_ASSERT_BOOL_CAST( x ) ((x) == 0 ? false : true)
  #else
  #  define BOOST_STATIC_ASSERT_BOOL_CAST(x) (bool)(x)
  #endif
  
  #ifdef BOOST_HAS_STATIC_ASSERT
  #  define BOOST_STATIC_ASSERT( B ) static_assert(B, #B)
  #else
  
  namespace boost{
  
  // HP aCC cannot deal with missing names for template value parameters
  template <bool x> struct STATIC_ASSERTION_FAILURE;
  
  template <> struct STATIC_ASSERTION_FAILURE<true> { enum { value = 1 }; };
  
  // HP aCC cannot deal with missing names for template value parameters
  template<int x> struct static_assert_test{};
  
  }
  
  //
  // Implicit instantiation requires that all member declarations be
  // instantiated, but that the definitions are *not* instantiated.
  //
  // It's not particularly clear how this applies to enum's or typedefs;
  // both are described as declarations [7.1.3] and [7.2] in the standard,
  // however some compilers use "delayed evaluation" of one or more of
  // these when implicitly instantiating templates.  We use typedef declarations
  // by default, but try defining BOOST_USE_ENUM_STATIC_ASSERT if the enum
  // version gets better results from your compiler...
  //
  // Implementation:
  // Both of these versions rely on sizeof(incomplete_type) generating an error
  // message containing the name of the incomplete type.  We use
  // "STATIC_ASSERTION_FAILURE" as the type name here to generate
  // an eye catching error message.  The result of the sizeof expression is either
  // used as an enum initialiser, or as a template argument depending which version
  // is in use...
  // Note that the argument to the assert is explicitly cast to bool using old-
  // style casts: too many compilers currently have problems with static_cast
  // when used inside integral constant expressions.
  //
  #if !defined(BOOST_BUGGY_INTEGRAL_CONSTANT_EXPRESSIONS)
  
  #if defined(BOOST_MSVC) && (BOOST_MSVC < 1300)
  // __LINE__ macro broken when -ZI is used see Q199057
  // fortunately MSVC ignores duplicate typedef's.
  #define BOOST_STATIC_ASSERT( B ) \
     typedef ::boost::static_assert_test<\
        sizeof(::boost::STATIC_ASSERTION_FAILURE< (bool)( B ) >)\
        > boost_static_assert_typedef_
  #elif defined(BOOST_MSVC)
  #define BOOST_STATIC_ASSERT( B ) \
     typedef ::boost::static_assert_test<\
        sizeof(::boost::STATIC_ASSERTION_FAILURE< BOOST_STATIC_ASSERT_BOOL_CAST ( B ) >)>\
           BOOST_JOIN(boost_static_assert_typedef_, __COUNTER__)
  #elif defined(BOOST_INTEL_CXX_VERSION) || defined(BOOST_SA_GCC_WORKAROUND)
  // agurt 15/sep/02: a special care is needed to force Intel C++ issue an error 
  // instead of warning in case of failure
  # define BOOST_STATIC_ASSERT( B ) \
      typedef char BOOST_JOIN(boost_static_assert_typedef_, __LINE__) \
          [ ::boost::STATIC_ASSERTION_FAILURE< BOOST_STATIC_ASSERT_BOOL_CAST( B ) >::value ]
  #elif defined(__sgi)
  // special version for SGI MIPSpro compiler
  #define BOOST_STATIC_ASSERT( B ) \
     BOOST_STATIC_CONSTANT(bool, \
       BOOST_JOIN(boost_static_assert_test_, __LINE__) = ( B )); \
     typedef ::boost::static_assert_test<\
       sizeof(::boost::STATIC_ASSERTION_FAILURE< \
         BOOST_JOIN(boost_static_assert_test_, __LINE__) >)>\
           BOOST_JOIN(boost_static_assert_typedef_, __LINE__)
  #elif BOOST_WORKAROUND(__MWERKS__, <= 0x3003)
  // special version for CodeWarrior <= 8.x
  #define BOOST_STATIC_ASSERT( B ) \
     BOOST_STATIC_CONSTANT(int, \
       BOOST_JOIN(boost_static_assert_test_, __LINE__) = \
         sizeof(::boost::STATIC_ASSERTION_FAILURE< BOOST_STATIC_ASSERT_BOOL_CAST( B ) >) )
  #else
  // generic version
  #define BOOST_STATIC_ASSERT( B ) \
     typedef ::boost::static_assert_test<\
        sizeof(::boost::STATIC_ASSERTION_FAILURE< BOOST_STATIC_ASSERT_BOOL_CAST( B ) >)>\
           BOOST_JOIN(boost_static_assert_typedef_, __LINE__)
  #endif
  
  #else
  // alternative enum based implementation:
  #define BOOST_STATIC_ASSERT( B ) \
     enum { BOOST_JOIN(boost_static_assert_enum_, __LINE__) \
        = sizeof(::boost::STATIC_ASSERTION_FAILURE< (bool)( B ) >) }
  #endif
  #endif // ndef BOOST_HAS_STATIC_ASSERT
  
  #endif // BOOST_STATIC_ASSERT_HPP
  
  
  