#ifndef BOOST_STATIC_WARNING_HPP

#define BOOST_STATIC_WARNING_HPP

//  (C) Copyright Robert Ramey 2003. Jonathan Turkanis 2004.

// Use, modification and distribution is subject to the Boost Software

// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at

// MS compatible compilers support #pragma once

#if defined(_MSC_VER) && (_MSC_VER >= 1020)

# pragma once

#endif

// http://www.boost.org/LICENSE_1_0.txt)

//  See http://www.boost.org/libs/static_assert for documentation.

/*

 Revision history:

   15 June  2003 - Initial version.

   31 March 2004 - improved diagnostic messages and portability 

                   (Jonathan Turkanis)

   03 April 2004 - works on VC6 at class and namespace scope

                 - ported to DigitalMars

                 - static warnings disabled by default; when enabled,

                   uses pragmas to enable required compiler warnings

                   on MSVC, Intel, Metrowerks and Borland 5.x.

                   (Jonathan Turkanis)

   30 May 2004   - tweaked for msvc 7.1 and gcc 3.3

                 - static warnings ENabled by default; when enabled,

                   (Robert Ramey)

*/

#include <boost/config.hpp>

//

// Implementation

// Makes use of the following warnings:

//  1. GCC prior to 3.3: division by zero.

//  2. BCC 6.0 preview: unreferenced local variable.

//  3. DigitalMars: returning address of local automatic variable.

//  4. VC6: class previously seen as struct (as in 'boost/mpl/print.hpp')

//  5. All others: deletion of pointer to incomplete type.

//

// The trick is to find code which produces warnings containing the name of

// a structure or variable. Details, with same numbering as above:

// 1. static_warning_impl<B>::value is zero iff B is false, so diving an int

//    by this value generates a warning iff B is false.

// 2. static_warning_impl<B>::type has a constructor iff B is true, so an

//    unreferenced variable of this type generates a warning iff B is false.

// 3. static_warning_impl<B>::type overloads operator& to return a dynamically

//    allocated int pointer only is B is true, so  returning the address of an

//    automatic variable of this type generates a warning iff B is fasle.

// 4. static_warning_impl<B>::STATIC_WARNING is decalred as a struct iff B is 

//    false. 

// 5. static_warning_impl<B>::type is incomplete iff B is false, so deleting a

//    pointer to this type generates a warning iff B is false.

//

//------------------Enable selected warnings----------------------------------//

// Enable the warnings relied on by BOOST_STATIC_WARNING, where possible. The 

// only pragma which is absolutely necessary here is for Borland 5.x, since 

// W8073 is disabled by default. If enabling selected warnings is considered 

// unacceptable, this section can be replaced with:

//   #if defined(__BORLANDC__) && (__BORLANDC__ <= 0x600)

//    pragma warn +stu

//   #endif

# if defined(BOOST_MSVC)

#  pragma warning(2:4150) // C4150: deletion of pointer to incomplete type 'type'.

# elif defined(BOOST_INTEL) && (defined(__WIN32__) || defined(WIN32))

#  pragma warning(2:457) // #457: delete of pointer to incomplete class.

# elif defined(__BORLANDC__) && (__BORLANDC__ <= 0x600)

#  pragma warn +stu  // W8073: Undefined structure 'structure'.

# elif defined(__MWERKS__)

#  pragma extended_errorcheck on // Enable 'extended error checking'.

# endif

//------------------Configure-------------------------------------------------//

# if defined(__BORLANDC__) && (__BORLANDC__ >= 0x600)

#  define BOOST_HAS_DESCRIPTIVE_UNREFERENCED_VARIABLE_WARNING

# elif defined(__GNUC__) && !defined(BOOST_INTEL) // && (__GNUC__ * 100 + __GNUC_MINOR__ <= 302)

#  define BOOST_HAS_DESCRIPTIVE_DIVIDE_BY_ZERO_WARNING

# elif defined(__DMC__)

#  define BOOST_HAS_DESCRIPTIVE_RETURNING_ADDRESS_OF_TEMPORARY_WARNING

# elif defined(BOOST_MSVC) // && (BOOST_MSVC < 1300)

#  define BOOST_NO_PREDEFINED_LINE_MACRO

#  pragma warning(disable:4094) // C4094: untagged 'stuct' declared no symbols

#endif

//------------------Helper templates------------------------------------------//

namespace boost {

struct STATIC_WARNING;

template<bool>

struct static_warning_impl;

template<>

struct static_warning_impl<false> {

    enum { value = 0 };

    #if !defined(BOOST_HAS_DESCRIPTIVE_UNREFERENCED_VARIABLE_WARNING) && \

        !defined(BOOST_HAS_DESCRIPTIVE_RETURNING_ADDRESS_OF_TEMPORARY_WARNING)

        typedef boost::STATIC_WARNING type;

    #else

        typedef int type;

    #endif

    #if defined(BOOST_NO_PREDEFINED_LINE_MACRO)

        struct STATIC_WARNING { };

    #endif

};

template<>

struct static_warning_impl<true> {

    enum { value = 1 };

    struct type { type() { } int* operator&() { return new int; } };

    #if defined(BOOST_NO_PREDEFINED_LINE_MACRO)

        class STATIC_WARNING { };

    #endif

};

} // namespace boost

//------------------Definition of BOOST_STATIC_WARNING------------------------//

#if defined(BOOST_HAS_DESCRIPTIVE_UNREFERENCED_VARIABLE_WARNING)

#    define BOOST_STATIC_WARNING_IMPL(B)                   \

     struct BOOST_JOIN(STATIC_WARNING, __LINE__) {         \

       void f() {                                          \

           ::boost::static_warning_impl<(bool)( B )>::type \

           STATIC_WARNING;                                 \

       }                                                   \

     }                                                     \

     /**/

#elif defined(BOOST_HAS_DESCRIPTIVE_RETURNING_ADDRESS_OF_TEMPORARY_WARNING)

#    define BOOST_STATIC_WARNING_IMPL(B)                        \

     struct BOOST_JOIN(STATIC_WARNING, __LINE__) {              \

        int* f() {                                              \

            ::boost::static_warning_impl<(bool)( B )>::type     \

            STATIC_WARNING;                                     \

            return &STATIC_WARNING;                             \

        }                                                       \

     }                                                          \

     /**/

#elif defined(BOOST_HAS_DESCRIPTIVE_DIVIDE_BY_ZERO_WARNING)

#    define BOOST_STATIC_WARNING_IMPL(B)                             \

     struct BOOST_JOIN(STATIC_WARNING, __LINE__) {                   \

         int f() { int STATIC_WARNING = 1;                           \

                   return STATIC_WARNING /                           \

                   boost::static_warning_impl<(bool)( B )>::value; } \

     }                                                               \

     /**/

#elif defined(BOOST_NO_PREDEFINED_LINE_MACRO) 

     // VC6; __LINE__ macro broken when -ZI is used see Q199057, so 

     // non-conforming workaround is used.

#    define BOOST_STATIC_WARNING_IMPL(B)                       \

     struct {                                                  \

        struct S {                                             \

            typedef boost::static_warning_impl<(bool)( B )> f; \

            friend class f::STATIC_WARNING;                    \

        };                                                     \

     }                                                         \

     /**/

#else // Deletion of pointer to incomplete type.

#    define BOOST_STATIC_WARNING_IMPL(B)                     \

     struct BOOST_JOIN(STATIC_WARNING, __LINE__) {           \

         ::boost::static_warning_impl<(bool)( B )>::type* p; \

         void f() { delete p; }                              \

     }                                                       \

     /**/

#endif

#ifndef BOOST_DISABLE_STATIC_WARNINGS

# define BOOST_STATIC_WARNING(B) BOOST_STATIC_WARNING_IMPL(B)

#else // #ifdef BOOST_ENABLE_STATIC_WARNINGS //-------------------------------//

# define BOOST_STATIC_WARNING(B) BOOST_STATIC_WARNING_IMPL(true)

#endif

#endif // BOOST_STATIC_WARNING_HPP