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#if defined(__GNUC__) && !defined(__GXX_EXPERIMENTAL_CXX0X__)
21//
22// This is horrible, but it seems to be the only we can shut up the
23// "anonymous variadic macros were introduced in C99 [-Wvariadic-macros]"
24// warning that get spewed out otherwise in non-C++11 mode.
25//
26#pragma GCC system_header
27#endif
28
29#ifndef BOOST_NO_CXX11_STATIC_ASSERT
30# ifndef BOOST_NO_CXX11_VARIADIC_MACROS
31# define BOOST_STATIC_ASSERT_MSG( ... ) static_assert(__VA_ARGS__)
32# else
33# define BOOST_STATIC_ASSERT_MSG( B, Msg ) BOOST_STATIC_ASSERT( B )
34# endif
35#else
36# define BOOST_STATIC_ASSERT_MSG( B, Msg ) BOOST_STATIC_ASSERT( B )
37#endif
38
39#ifdef __BORLANDC__
40//
41// workaround for buggy integral-constant expression support:
42#define BOOST_BUGGY_INTEGRAL_CONSTANT_EXPRESSIONS
43#endif
44
45#if defined(__GNUC__) && (__GNUC__ == 3) && ((__GNUC_MINOR__ == 3) || (__GNUC_MINOR__ == 4))
46// gcc 3.3 and 3.4 don't produce good error messages with the default version:
47# define BOOST_SA_GCC_WORKAROUND
48#endif
49
50//
51// If the compiler issues warnings about old C style casts,
52// then enable this:
53//
54#if defined(__GNUC__) && ((__GNUC__ > 3) || ((__GNUC__ == 3) && (__GNUC_MINOR__ >= 4)))
55# ifndef BOOST_NO_CXX11_VARIADIC_MACROS
56# define BOOST_STATIC_ASSERT_BOOL_CAST( ... ) ((__VA_ARGS__) == 0 ? false : true)
57# else
58# define BOOST_STATIC_ASSERT_BOOL_CAST( x ) ((x) == 0 ? false : true)
59# endif
60#else
61# ifndef BOOST_NO_CXX11_VARIADIC_MACROS
62# define BOOST_STATIC_ASSERT_BOOL_CAST( ... ) (bool)(__VA_ARGS__)
63# else
64# define BOOST_STATIC_ASSERT_BOOL_CAST(x) (bool)(x)
65# endif
66#endif
67//
68// If the compiler warns about unused typedefs then enable this:
69//
70#if defined(__GNUC__) && ((__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 7)))
71# define BOOST_STATIC_ASSERT_UNUSED_ATTRIBUTE __attribute__((unused))
72#else
73# define BOOST_STATIC_ASSERT_UNUSED_ATTRIBUTE
74#endif
75
76#ifndef BOOST_NO_CXX11_STATIC_ASSERT
77# ifndef BOOST_NO_CXX11_VARIADIC_MACROS
78# define BOOST_STATIC_ASSERT( ... ) static_assert(__VA_ARGS__, #__VA_ARGS__)
79# else
80# define BOOST_STATIC_ASSERT( B ) static_assert(B, #B)
81# endif
82#else
83
84namespace boost{
85
86// HP aCC cannot deal with missing names for template value parameters
87template <bool x> struct STATIC_ASSERTION_FAILURE;
88
89template <> struct STATIC_ASSERTION_FAILURE<true> { enum { value = 1 }; };
90
91// HP aCC cannot deal with missing names for template value parameters
92template<int x> struct static_assert_test{};
93
94}
95
96//
97// Implicit instantiation requires that all member declarations be
98// instantiated, but that the definitions are *not* instantiated.
99//
100// It's not particularly clear how this applies to enum's or typedefs;
101// both are described as declarations [7.1.3] and [7.2] in the standard,
102// however some compilers use "delayed evaluation" of one or more of
103// these when implicitly instantiating templates. We use typedef declarations
104// by default, but try defining BOOST_USE_ENUM_STATIC_ASSERT if the enum
105// version gets better results from your compiler...
106//
107// Implementation:
108// Both of these versions rely on sizeof(incomplete_type) generating an error
109// message containing the name of the incomplete type. We use
110// "STATIC_ASSERTION_FAILURE" as the type name here to generate
111// an eye catching error message. The result of the sizeof expression is either
112// used as an enum initialiser, or as a template argument depending which version
113// is in use...
114// Note that the argument to the assert is explicitly cast to bool using old-
115// style casts: too many compilers currently have problems with static_cast
116// when used inside integral constant expressions.
117//
118#if !defined(BOOST_BUGGY_INTEGRAL_CONSTANT_EXPRESSIONS)
119
120#if defined(BOOST_MSVC) && (BOOST_MSVC < 1300)
121// __LINE__ macro broken when -ZI is used see Q199057
122// fortunately MSVC ignores duplicate typedef's.
123#define BOOST_STATIC_ASSERT( B ) \
124 typedef ::boost::static_assert_test<\
125 sizeof(::boost::STATIC_ASSERTION_FAILURE< (bool)( B ) >)\
126 > boost_static_assert_typedef_
127#elif defined(BOOST_MSVC) && defined(BOOST_NO_CXX11_VARIADIC_MACROS)
128#define BOOST_STATIC_ASSERT( B ) \
129 typedef ::boost::static_assert_test<\
130 sizeof(::boost::STATIC_ASSERTION_FAILURE< BOOST_STATIC_ASSERT_BOOL_CAST ( B ) >)>\
131 BOOST_JOIN(boost_static_assert_typedef_, __COUNTER__)
132#elif defined(BOOST_MSVC)
133#define BOOST_STATIC_ASSERT(...) \
134 typedef ::boost::static_assert_test<\
135 sizeof(::boost::STATIC_ASSERTION_FAILURE< BOOST_STATIC_ASSERT_BOOL_CAST (__VA_ARGS__) >)>\
136 BOOST_JOIN(boost_static_assert_typedef_, __COUNTER__)
137#elif (defined(BOOST_INTEL_CXX_VERSION) || defined(BOOST_SA_GCC_WORKAROUND)) && defined(BOOST_NO_CXX11_VARIADIC_MACROS)
138// agurt 15/sep/02: a special care is needed to force Intel C++ issue an error
139// instead of warning in case of failure
140# define BOOST_STATIC_ASSERT( B ) \
141 typedef char BOOST_JOIN(boost_static_assert_typedef_, __LINE__) \
142 [ ::boost::STATIC_ASSERTION_FAILURE< BOOST_STATIC_ASSERT_BOOL_CAST( B ) >::value ]
143#elif (defined(BOOST_INTEL_CXX_VERSION) || defined(BOOST_SA_GCC_WORKAROUND)) && !defined(BOOST_NO_CXX11_VARIADIC_MACROS)
144// agurt 15/sep/02: a special care is needed to force Intel C++ issue an error
145// instead of warning in case of failure
146# define BOOST_STATIC_ASSERT(...) \
147 typedef char BOOST_JOIN(boost_static_assert_typedef_, __LINE__) \
148 [ ::boost::STATIC_ASSERTION_FAILURE< BOOST_STATIC_ASSERT_BOOL_CAST( __VA_ARGS__ ) >::value ]
149#elif defined(__sgi)
150// special version for SGI MIPSpro compiler
151#define BOOST_STATIC_ASSERT( B ) \
152 BOOST_STATIC_CONSTANT(bool, \
153 BOOST_JOIN(boost_static_assert_test_, __LINE__) = ( B )); \
154 typedef ::boost::static_assert_test<\
155 sizeof(::boost::STATIC_ASSERTION_FAILURE< \
156 BOOST_JOIN(boost_static_assert_test_, __LINE__) >)>\
157 BOOST_JOIN(boost_static_assert_typedef_, __LINE__)
158#elif BOOST_WORKAROUND(__MWERKS__, <= 0x3003)
159// special version for CodeWarrior <= 8.x
160#define BOOST_STATIC_ASSERT( B ) \
161 BOOST_STATIC_CONSTANT(int, \
162 BOOST_JOIN(boost_static_assert_test_, __LINE__) = \
163 sizeof(::boost::STATIC_ASSERTION_FAILURE< BOOST_STATIC_ASSERT_BOOL_CAST( B ) >) )
164#else
165// generic version
166# ifndef BOOST_NO_CXX11_VARIADIC_MACROS
167# define BOOST_STATIC_ASSERT( ... ) \
168 typedef ::boost::static_assert_test<\
169 sizeof(::boost::STATIC_ASSERTION_FAILURE< BOOST_STATIC_ASSERT_BOOL_CAST( __VA_ARGS__ ) >)>\
170 BOOST_JOIN(boost_static_assert_typedef_, __LINE__) BOOST_STATIC_ASSERT_UNUSED_ATTRIBUTE
171# else
172# define BOOST_STATIC_ASSERT( B ) \
173 typedef ::boost::static_assert_test<\
174 sizeof(::boost::STATIC_ASSERTION_FAILURE< BOOST_STATIC_ASSERT_BOOL_CAST( B ) >)>\
175 BOOST_JOIN(boost_static_assert_typedef_, __LINE__) BOOST_STATIC_ASSERT_UNUSED_ATTRIBUTE
176# endif
177#endif
178
179#else
180// alternative enum based implementation:
181# ifndef BOOST_NO_CXX11_VARIADIC_MACROS
182# define BOOST_STATIC_ASSERT( ... ) \
183 enum { BOOST_JOIN(boost_static_assert_enum_, __LINE__) \
184 = sizeof(::boost::STATIC_ASSERTION_FAILURE< (bool)( __VA_ARGS__ ) >) }
185# else
186# define BOOST_STATIC_ASSERT(B) \
187 enum { BOOST_JOIN(boost_static_assert_enum_, __LINE__) \
188 = sizeof(::boost::STATIC_ASSERTION_FAILURE< (bool)( B ) >) }
189# endif
190#endif
191#endif // defined(BOOST_NO_CXX11_STATIC_ASSERT)
192
193#endif // BOOST_STATIC_ASSERT_HPP
194
195
196