//  (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