boost/static_assert.hpp
// (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> #include <cstddef> //for std::size_t #if defined(__GNUC__) && !defined(__GXX_EXPERIMENTAL_CXX0X__) // // This is horrible, but it seems to be the only we can shut up the // "anonymous variadic macros were introduced in C99 [-Wvariadic-macros]" // warning that get spewed out otherwise in non-C++11 mode. // #pragma GCC system_header #endif #ifndef BOOST_NO_CXX11_STATIC_ASSERT # ifndef BOOST_NO_CXX11_VARIADIC_MACROS # define BOOST_STATIC_ASSERT_MSG( ... ) static_assert(__VA_ARGS__) # else # define BOOST_STATIC_ASSERT_MSG( B, Msg ) static_assert( B, Msg ) # endif #else # define BOOST_STATIC_ASSERT_MSG( B, Msg ) BOOST_STATIC_ASSERT( B ) #endif #ifdef BOOST_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))) # ifndef BOOST_NO_CXX11_VARIADIC_MACROS # define BOOST_STATIC_ASSERT_BOOL_CAST( ... ) ((__VA_ARGS__) != 0) # else # define BOOST_STATIC_ASSERT_BOOL_CAST( x ) ((x) != 0) # endif #else # ifndef BOOST_NO_CXX11_VARIADIC_MACROS # define BOOST_STATIC_ASSERT_BOOL_CAST( ... ) (bool)(__VA_ARGS__) # else # define BOOST_STATIC_ASSERT_BOOL_CAST(x) (bool)(x) # endif #endif #ifndef BOOST_NO_CXX11_STATIC_ASSERT # ifndef BOOST_NO_CXX11_VARIADIC_MACROS # define BOOST_STATIC_ASSERT( ... ) static_assert(__VA_ARGS__, #__VA_ARGS__) # else # define BOOST_STATIC_ASSERT( B ) static_assert(B, #B) # endif #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<std::size_t 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) && defined(BOOST_NO_CXX11_VARIADIC_MACROS) #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_MSVC) #define BOOST_STATIC_ASSERT(...) \ typedef ::boost::static_assert_test<\ sizeof(::boost::STATIC_ASSERTION_FAILURE< BOOST_STATIC_ASSERT_BOOL_CAST (__VA_ARGS__) >)>\ BOOST_JOIN(boost_static_assert_typedef_, __COUNTER__) #elif (defined(BOOST_INTEL_CXX_VERSION) || defined(BOOST_SA_GCC_WORKAROUND)) && defined(BOOST_NO_CXX11_VARIADIC_MACROS) // 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(BOOST_INTEL_CXX_VERSION) || defined(BOOST_SA_GCC_WORKAROUND)) && !defined(BOOST_NO_CXX11_VARIADIC_MACROS) // 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(...) \ typedef char BOOST_JOIN(boost_static_assert_typedef_, __LINE__) \ [ ::boost::STATIC_ASSERTION_FAILURE< BOOST_STATIC_ASSERT_BOOL_CAST( __VA_ARGS__ ) >::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 # ifndef BOOST_NO_CXX11_VARIADIC_MACROS # define BOOST_STATIC_ASSERT( ... ) \ typedef ::boost::static_assert_test<\ sizeof(::boost::STATIC_ASSERTION_FAILURE< BOOST_STATIC_ASSERT_BOOL_CAST( __VA_ARGS__ ) >)>\ BOOST_JOIN(boost_static_assert_typedef_, __LINE__) BOOST_ATTRIBUTE_UNUSED # else # 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__) BOOST_ATTRIBUTE_UNUSED # endif #endif #else // alternative enum based implementation: # ifndef BOOST_NO_CXX11_VARIADIC_MACROS # define BOOST_STATIC_ASSERT( ... ) \ enum { BOOST_JOIN(boost_static_assert_enum_, __LINE__) \ = sizeof(::boost::STATIC_ASSERTION_FAILURE< (bool)( __VA_ARGS__ ) >) } # else # define BOOST_STATIC_ASSERT(B) \ enum { BOOST_JOIN(boost_static_assert_enum_, __LINE__) \ = sizeof(::boost::STATIC_ASSERTION_FAILURE< (bool)( B ) >) } # endif #endif #endif // defined(BOOST_NO_CXX11_STATIC_ASSERT) #endif // BOOST_STATIC_ASSERT_HPP