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 ) static_assert( B, Msg )
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#ifndef BOOST_NO_CXX11_STATIC_ASSERT
69# ifndef BOOST_NO_CXX11_VARIADIC_MACROS
70# define BOOST_STATIC_ASSERT( ... ) static_assert(__VA_ARGS__, #__VA_ARGS__)
71# else
72# define BOOST_STATIC_ASSERT( B ) static_assert(B, #B)
73# endif
74#else
75
76namespace boost{
77
78// HP aCC cannot deal with missing names for template value parameters
79template <bool x> struct STATIC_ASSERTION_FAILURE;
80
81template <> struct STATIC_ASSERTION_FAILURE<true> { enum { value = 1 }; };
82
83// HP aCC cannot deal with missing names for template value parameters
84template<int x> struct static_assert_test{};
85
86}
87
88//
89// Implicit instantiation requires that all member declarations be
90// instantiated, but that the definitions are *not* instantiated.
91//
92// It's not particularly clear how this applies to enum's or typedefs;
93// both are described as declarations [7.1.3] and [7.2] in the standard,
94// however some compilers use "delayed evaluation" of one or more of
95// these when implicitly instantiating templates. We use typedef declarations
96// by default, but try defining BOOST_USE_ENUM_STATIC_ASSERT if the enum
97// version gets better results from your compiler...
98//
99// Implementation:
100// Both of these versions rely on sizeof(incomplete_type) generating an error
101// message containing the name of the incomplete type. We use
102// "STATIC_ASSERTION_FAILURE" as the type name here to generate
103// an eye catching error message. The result of the sizeof expression is either
104// used as an enum initialiser, or as a template argument depending which version
105// is in use...
106// Note that the argument to the assert is explicitly cast to bool using old-
107// style casts: too many compilers currently have problems with static_cast
108// when used inside integral constant expressions.
109//
110#if !defined(BOOST_BUGGY_INTEGRAL_CONSTANT_EXPRESSIONS)
111
112#if defined(BOOST_MSVC) && defined(BOOST_NO_CXX11_VARIADIC_MACROS)
113#define BOOST_STATIC_ASSERT( B ) \
114 typedef ::boost::static_assert_test<\
115 sizeof(::boost::STATIC_ASSERTION_FAILURE< BOOST_STATIC_ASSERT_BOOL_CAST ( B ) >)>\
116 BOOST_JOIN(boost_static_assert_typedef_, __COUNTER__)
117#elif defined(BOOST_MSVC)
118#define BOOST_STATIC_ASSERT(...) \
119 typedef ::boost::static_assert_test<\
120 sizeof(::boost::STATIC_ASSERTION_FAILURE< BOOST_STATIC_ASSERT_BOOL_CAST (__VA_ARGS__) >)>\
121 BOOST_JOIN(boost_static_assert_typedef_, __COUNTER__)
122#elif (defined(BOOST_INTEL_CXX_VERSION) || defined(BOOST_SA_GCC_WORKAROUND)) && defined(BOOST_NO_CXX11_VARIADIC_MACROS)
123// agurt 15/sep/02: a special care is needed to force Intel C++ issue an error
124// instead of warning in case of failure
125# define BOOST_STATIC_ASSERT( B ) \
126 typedef char BOOST_JOIN(boost_static_assert_typedef_, __LINE__) \
127 [ ::boost::STATIC_ASSERTION_FAILURE< BOOST_STATIC_ASSERT_BOOL_CAST( B ) >::value ]
128#elif (defined(BOOST_INTEL_CXX_VERSION) || defined(BOOST_SA_GCC_WORKAROUND)) && !defined(BOOST_NO_CXX11_VARIADIC_MACROS)
129// agurt 15/sep/02: a special care is needed to force Intel C++ issue an error
130// instead of warning in case of failure
131# define BOOST_STATIC_ASSERT(...) \
132 typedef char BOOST_JOIN(boost_static_assert_typedef_, __LINE__) \
133 [ ::boost::STATIC_ASSERTION_FAILURE< BOOST_STATIC_ASSERT_BOOL_CAST( __VA_ARGS__ ) >::value ]
134#elif defined(__sgi)
135// special version for SGI MIPSpro compiler
136#define BOOST_STATIC_ASSERT( B ) \
137 BOOST_STATIC_CONSTANT(bool, \
138 BOOST_JOIN(boost_static_assert_test_, __LINE__) = ( B )); \
139 typedef ::boost::static_assert_test<\
140 sizeof(::boost::STATIC_ASSERTION_FAILURE< \
141 BOOST_JOIN(boost_static_assert_test_, __LINE__) >)>\
142 BOOST_JOIN(boost_static_assert_typedef_, __LINE__)
143#elif BOOST_WORKAROUND(__MWERKS__, <= 0x3003)
144// special version for CodeWarrior <= 8.x
145#define BOOST_STATIC_ASSERT( B ) \
146 BOOST_STATIC_CONSTANT(int, \
147 BOOST_JOIN(boost_static_assert_test_, __LINE__) = \
148 sizeof(::boost::STATIC_ASSERTION_FAILURE< BOOST_STATIC_ASSERT_BOOL_CAST( B ) >) )
149#else
150// generic version
151# ifndef BOOST_NO_CXX11_VARIADIC_MACROS
152# define BOOST_STATIC_ASSERT( ... ) \
153 typedef ::boost::static_assert_test<\
154 sizeof(::boost::STATIC_ASSERTION_FAILURE< BOOST_STATIC_ASSERT_BOOL_CAST( __VA_ARGS__ ) >)>\
155 BOOST_JOIN(boost_static_assert_typedef_, __LINE__) BOOST_ATTRIBUTE_UNUSED
156# else
157# define BOOST_STATIC_ASSERT( B ) \
158 typedef ::boost::static_assert_test<\
159 sizeof(::boost::STATIC_ASSERTION_FAILURE< BOOST_STATIC_ASSERT_BOOL_CAST( B ) >)>\
160 BOOST_JOIN(boost_static_assert_typedef_, __LINE__) BOOST_ATTRIBUTE_UNUSED
161# endif
162#endif
163
164#else
165// alternative enum based implementation:
166# ifndef BOOST_NO_CXX11_VARIADIC_MACROS
167# define BOOST_STATIC_ASSERT( ... ) \
168 enum { BOOST_JOIN(boost_static_assert_enum_, __LINE__) \
169 = sizeof(::boost::STATIC_ASSERTION_FAILURE< (bool)( __VA_ARGS__ ) >) }
170# else
171# define BOOST_STATIC_ASSERT(B) \
172 enum { BOOST_JOIN(boost_static_assert_enum_, __LINE__) \
173 = sizeof(::boost::STATIC_ASSERTION_FAILURE< (bool)( B ) >) }
174# endif
175#endif
176#endif // defined(BOOST_NO_CXX11_STATIC_ASSERT)
177
178#endif // BOOST_STATIC_ASSERT_HPP
179
180
181