lyx_mirror/boost/boost/static_assert.hpp
Lars Gullik Bjønnes b9a9f9fca1 some new boost files that we now use
git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@2080 a592a061-630c-0410-9148-cb99ea01b6c8
2001-06-01 11:56:18 +00:00

96 lines
3.4 KiB
C++

// (C) Copyright John Maddock 2000.
// Permission to copy, use, modify, sell and
// distribute this software is granted provided this copyright notice appears
// in all copies. This software is provided "as is" without express or implied
// warranty, and with no claim as to its suitability for any purpose.
// See http://www.boost.org for most recent version including documentation.
/*
Revision history:
02 August 2000
Initial version.
*/
#ifndef BOOST_STATIC_ASSERT_HPP
#define BOOST_STATIC_ASSERT_HPP
#include <boost/config.hpp>
#ifdef __BORLANDC__
//
// workaround for buggy integral-constant expression support:
#define BOOST_BUGGY_INTEGRAL_CONSTANT_EXPRESSIONS
#endif
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>{};
// 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) && !defined(__MWERKS__)
#ifndef BOOST_MSVC
#define BOOST_STATIC_ASSERT( B ) \
typedef ::boost::static_assert_test<\
sizeof(::boost::STATIC_ASSERTION_FAILURE< (bool)( B ) >)>\
BOOST_ASSERT_JOIN(boost_static_assert_typedef_, __LINE__)
#else
// __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_
#endif
#else
// alternative enum based implementation:
#define BOOST_STATIC_ASSERT( B ) \
enum { BOOST_ASSERT_JOIN(boost_static_assert_enum_, __LINE__) \
= sizeof(::boost::STATIC_ASSERTION_FAILURE< (bool)( B ) >) }
#endif
//
// The following piece of macro magic joins the two
// arguments together, even when one of the arguments is
// itself a macro (see 16.3.1 in C++ standard). The key
// is that macro expansion of macro arguments does not
// occur in BOOST_DO_ASSERT_JOIN but does in BOOST_ASSERT_JOIN
// provided it is called from within another macro.
#define BOOST_ASSERT_JOIN( X, Y ) BOOST_DO_ASSERT_JOIN( X, Y )
#define BOOST_DO_ASSERT_JOIN( X, Y ) X##Y
#endif // BOOST_STATIC_ASSERT_HPP