1 //  (C) Copyright John Maddock 2000.
2 //  Use, modification and distribution are subject to the
3 //  Boost Software License, Version 1.0. (See accompanying file
4 //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
5 
6 //  See http://www.boost.org/libs/static_assert for documentation.
7 
8 /*
9  Revision history:
10    02 August 2000
11       Initial version.
12 */
13 
14 #ifndef BOOST_STATIC_ASSERT_HPP
15 #define BOOST_STATIC_ASSERT_HPP
16 
17 #include <boost/config.hpp>
18 #include <boost/detail/workaround.hpp>
19 
20 #ifndef BOOST_NO_STATIC_ASSERT
21 #  define BOOST_STATIC_ASSERT_MSG( B, Msg ) static_assert(B, Msg)
22 #else
23 #  define BOOST_STATIC_ASSERT_MSG( B, Msg ) BOOST_STATIC_ASSERT( B )
24 #endif
25 
26 #ifdef __BORLANDC__
27 //
28 // workaround for buggy integral-constant expression support:
29 #define BOOST_BUGGY_INTEGRAL_CONSTANT_EXPRESSIONS
30 #endif
31 
32 #if defined(__GNUC__) && (__GNUC__ == 3) && ((__GNUC_MINOR__ == 3) || (__GNUC_MINOR__ == 4))
33 // gcc 3.3 and 3.4 don't produce good error messages with the default version:
34 #  define BOOST_SA_GCC_WORKAROUND
35 #endif
36 
37 //
38 // If the compiler issues warnings about old C style casts,
39 // then enable this:
40 //
41 #if defined(__GNUC__) && ((__GNUC__ > 3) || ((__GNUC__ == 3) && (__GNUC_MINOR__ >= 4)))
42 #  define BOOST_STATIC_ASSERT_BOOL_CAST( x ) ((x) == 0 ? false : true)
43 #else
44 #  define BOOST_STATIC_ASSERT_BOOL_CAST(x) (bool)(x)
45 #endif
46 
47 #ifndef BOOST_NO_STATIC_ASSERT
48 #  define BOOST_STATIC_ASSERT( B ) static_assert(B, #B)
49 #else
50 
51 namespace boost{
52 
53 // HP aCC cannot deal with missing names for template value parameters
54 template <bool x> struct STATIC_ASSERTION_FAILURE;
55 
56 template <> struct STATIC_ASSERTION_FAILURE<true> { enum { value = 1 }; };
57 
58 // HP aCC cannot deal with missing names for template value parameters
59 template<int x> struct static_assert_test{};
60 
61 }
62 
63 //
64 // Implicit instantiation requires that all member declarations be
65 // instantiated, but that the definitions are *not* instantiated.
66 //
67 // It's not particularly clear how this applies to enum's or typedefs;
68 // both are described as declarations [7.1.3] and [7.2] in the standard,
69 // however some compilers use "delayed evaluation" of one or more of
70 // these when implicitly instantiating templates.  We use typedef declarations
71 // by default, but try defining BOOST_USE_ENUM_STATIC_ASSERT if the enum
72 // version gets better results from your compiler...
73 //
74 // Implementation:
75 // Both of these versions rely on sizeof(incomplete_type) generating an error
76 // message containing the name of the incomplete type.  We use
77 // "STATIC_ASSERTION_FAILURE" as the type name here to generate
78 // an eye catching error message.  The result of the sizeof expression is either
79 // used as an enum initialiser, or as a template argument depending which version
80 // is in use...
81 // Note that the argument to the assert is explicitly cast to bool using old-
82 // style casts: too many compilers currently have problems with static_cast
83 // when used inside integral constant expressions.
84 //
85 #if !defined(BOOST_BUGGY_INTEGRAL_CONSTANT_EXPRESSIONS)
86 
87 #if defined(BOOST_MSVC) && (BOOST_MSVC < 1300)
88 // __LINE__ macro broken when -ZI is used see Q199057
89 // fortunately MSVC ignores duplicate typedef's.
90 #define BOOST_STATIC_ASSERT( B ) \
91    typedef ::boost::static_assert_test<\
92       sizeof(::boost::STATIC_ASSERTION_FAILURE< (bool)( B ) >)\
93       > boost_static_assert_typedef_
94 #elif defined(BOOST_MSVC)
95 #define BOOST_STATIC_ASSERT( B ) \
96    typedef ::boost::static_assert_test<\
97       sizeof(::boost::STATIC_ASSERTION_FAILURE< BOOST_STATIC_ASSERT_BOOL_CAST ( B ) >)>\
98          BOOST_JOIN(boost_static_assert_typedef_, __COUNTER__)
99 #elif defined(BOOST_INTEL_CXX_VERSION) || defined(BOOST_SA_GCC_WORKAROUND)
100 // agurt 15/sep/02: a special care is needed to force Intel C++ issue an error
101 // instead of warning in case of failure
102 # define BOOST_STATIC_ASSERT( B ) \
103     typedef char BOOST_JOIN(boost_static_assert_typedef_, __LINE__) \
104         [ ::boost::STATIC_ASSERTION_FAILURE< BOOST_STATIC_ASSERT_BOOL_CAST( B ) >::value ]
105 #elif defined(__sgi)
106 // special version for SGI MIPSpro compiler
107 #define BOOST_STATIC_ASSERT( B ) \
108    BOOST_STATIC_CONSTANT(bool, \
109      BOOST_JOIN(boost_static_assert_test_, __LINE__) = ( B )); \
110    typedef ::boost::static_assert_test<\
111      sizeof(::boost::STATIC_ASSERTION_FAILURE< \
112        BOOST_JOIN(boost_static_assert_test_, __LINE__) >)>\
113          BOOST_JOIN(boost_static_assert_typedef_, __LINE__)
114 #elif BOOST_WORKAROUND(__MWERKS__, <= 0x3003)
115 // special version for CodeWarrior <= 8.x
116 #define BOOST_STATIC_ASSERT( B ) \
117    BOOST_STATIC_CONSTANT(int, \
118      BOOST_JOIN(boost_static_assert_test_, __LINE__) = \
119        sizeof(::boost::STATIC_ASSERTION_FAILURE< BOOST_STATIC_ASSERT_BOOL_CAST( B ) >) )
120 #else
121 // generic version
122 #define BOOST_STATIC_ASSERT( B ) \
123    typedef ::boost::static_assert_test<\
124       sizeof(::boost::STATIC_ASSERTION_FAILURE< BOOST_STATIC_ASSERT_BOOL_CAST( B ) >)>\
125          BOOST_JOIN(boost_static_assert_typedef_, __LINE__)
126 #endif
127 
128 #else
129 // alternative enum based implementation:
130 #define BOOST_STATIC_ASSERT( B ) \
131    enum { BOOST_JOIN(boost_static_assert_enum_, __LINE__) \
132       = sizeof(::boost::STATIC_ASSERTION_FAILURE< (bool)( B ) >) }
133 #endif
134 #endif // defined(BOOST_NO_STATIC_ASSERT)
135 
136 #endif // BOOST_STATIC_ASSERT_HPP
137 
138 
139