Branch at revision 46530

[SVN r46531]

Jamfile.v2

@@ -0,0 +1,31 @@
+# copyright John Maddock 2003
+# 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)
+
+# bring in the rules for testing
+import testing ;
+
+test-suite static_assert :
+	[ run static_assert_test.cpp ]
+#	[ run static_assert_example_1.cpp ]
+	[ run static_assert_example_2.cpp ]
+	[ run static_assert_example_3.cpp ]
+	[ compile-fail static_assert_test_fail_1.cpp ]
+	[ compile-fail static_assert_test_fail_2.cpp ]
+	[ compile-fail static_assert_test_fail_3.cpp ]
+	[ compile-fail static_assert_test_fail_4.cpp ]
+	[ compile-fail static_assert_test_fail_5.cpp ]
+	[ compile-fail static_assert_test_fail_6.cpp ]
+	[ compile-fail static_assert_test_fail_7.cpp ]
+	[ compile-fail static_assert_test_fail_8.cpp ]
+	[ compile-fail static_assert_test_fail_9.cpp ]
+	[ compile-fail static_assert_test_fail_10.cpp ]
+;
+
+
+
+
+
+
+

doc/Jamfile.v2

@@ -0,0 +1,20 @@
+
+# Copyright John Maddock 2005. 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)
+
+using quickbook ;
+
+xml static_assert : static_assert.qbk ;
+boostbook standalone
+    :
+        static_assert
+    :
+        <xsl:param>nav.layout=none
+        <xsl:param>navig.graphics=0
+    ;
+
+install html : ../../../doc/html/boostbook.css ;
+install ../ : ../../../boost.png ;
+
+

doc/static_assert.qbk

@@ -0,0 +1,230 @@
+[library Boost.StaticAssert
+    [copyright 2000 2005 Steve Cleary and John Maddock]
+    [purpose Compile time diagnostics library]
+    [license
+        Distributed under the Boost Software License, Version 1.0.
+        (See accompanying file LICENSE_1_0.txt or copy at
+        <ulink url="http://www.boost.org/LICENSE_1_0.txt">
+            http://www.boost.org/LICENSE_1_0.txt
+        </ulink>)
+    ]
+    [authors [Maddock, John], [Cleary, Steve]]
+    [category template]
+    [category testing]
+    [category generic]
+    [last-revision $Date$]
+]
+
+This manual is also available in 
+[@http:svn.boost.org/svn/boost/sandbox/pdf/static_assert/release/static_assert.pdf 
+printer friendly PDF format].
+
+[section:intro Overview and Tutorial]
+
+The header `<boost/static_assert.hpp>` supplies a single macro `BOOST_STATIC_ASSERT(x)`, 
+which generates a compile time error message if the integral-constant-expression `x`
+is not true. In other words it is the compile time equivalent of the assert macro; 
+this is sometimes known as a "compile-time-assertion", but will be called a 
+"static assertion" throughout these docs. Note that if the condition is `true`, 
+then the macro will generate neither code nor data - and the macro can also 
+be used at either namespace, class or function scope. When used in a template, 
+the static assertion will be evaluated at the time the template is instantiated; 
+this is particularly useful for validating template parameters. 
+
+One of the aims of `BOOST_STATIC_ASSERT` is to generate readable error messages. 
+These immediately tell the user that a library is being used in a manner that 
+is not supported. While error messages obviously differ from compiler to compiler, 
+but you should see something like: 
+
+   Illegal use of STATIC_ASSERTION_FAILURE<false>
+
+Which is intended to at least catch the eye!
+
+You can use `BOOST_STATIC_ASSERT` at any place where you can place a declaration, 
+that is at class, function or namespace scope, this is illustrated by the 
+following examples:
+
+[section:namespace Use at namespace scope.]
+
+The macro can be used at namespace scope, if there is some requirement must 
+always be true; generally this means some platform specific requirement. 
+Suppose we require that `int` be at least a 32-bit integral type, and that `wchar_t` 
+be an unsigned type. We can verify this at compile time as follows:
+
+   #include <climits>
+   #include <cwchar>
+   #include <limits>
+   #include <boost/static_assert.hpp>
+
+   namespace my_conditions {
+
+      BOOST_STATIC_ASSERT(std::numeric_limits<int>::digits >= 32);
+      BOOST_STATIC_ASSERT(WCHAR_MIN >= 0);
+
+   } // namespace my_conditions
+
+The use of the namespace my_conditions here requires some comment. 
+The macro `BOOST_STATIC_ASSERT` works by generating an typedef declaration, 
+and since the typedef must have a name, the macro generates one automatically by 
+mangling a stub name with the value of `__LINE__`. When `BOOST_STATIC_ASSERT` is 
+used at either class or function scope then each use of `BOOST_STATIC_ASSERT` 
+is guaranteed to produce a name unique to that scope (provided you only use 
+the macro once on each line). However when used in a header at namespace 
+scope, that namespace can be continued over multiple headers, each of which 
+may have their own static assertions, and on the "same" lines, thereby generating 
+duplicate declarations. In theory the compiler should silently ignore duplicate 
+typedef declarations, however many do not do so (and even if they do they are 
+entitled to emit warnings in such cases). To avoid potential problems, if you 
+use `BOOST_STATIC_ASSERT` in a header and at namespace scope, then enclose 
+them in a namespace unique to that header.
+
+[endsect]
+
+[section:function Use at function scope]
+
+The macro is typically used at function scope inside template functions, 
+when the template arguments need checking. Imagine that we have an 
+iterator-based algorithm that requires random access iterators. 
+If the algorithm is instantiated with iterators that do not meet our 
+requirements then an error will be generated eventually, but this may 
+be nested deep inside several templates, making it hard for the user to 
+determine what went wrong. One option is to add a static assertion at 
+the top level of the template, in that case if the condition is not met, 
+then an error will be generated in a way that makes it reasonably obvious to 
+the user that the template is being misused.
+
+   #include <iterator>
+   #include <boost/static_assert.hpp>
+   #include <boost/type_traits.hpp>
+
+   template <class RandomAccessIterator >
+   RandomAccessIterator foo(RandomAccessIterator from, 
+                            RandomAccessIterator to)
+   {
+      // this template can only be used with
+      // random access iterators...
+      typedef typename std::iterator_traits< 
+            RandomAccessIterator >::iterator_category cat;
+      BOOST_STATIC_ASSERT(
+         (boost::is_convertible<
+            cat, 
+            const std::random_access_iterator_tag&>::value));
+      //
+      // detail goes here...
+      return from;
+   }
+
+A couple of footnotes are in order here: the extra set of parenthesis around the 
+assert, is to prevent the comma inside the `is_convertible` template being 
+interpreted by the preprocessor as a macro argument separator; the target type 
+for `is_convertible` is a reference type, as some compilers have problems 
+using `is_convertible` when the conversion is via a user defined constructor 
+(in any case there is no guarantee that the iterator tag classes are 
+copy-constructible).
+
+[endsect]
+
+[section:class Use at class scope]
+
+The macro is typically used inside classes that are templates. 
+Suppose we have a template-class that requires an unsigned integral type with 
+at least 16-bits of precision as a template argument, we can achieve this 
+using something like this:
+
+   #include <climits>
+   #include <boost/static_assert.hpp>
+
+   template <class UnsignedInt>
+   class myclass
+   {
+   private:
+      BOOST_STATIC_ASSERT((std::numeric_limits<UnsignedInt>::digits >= 16)
+                           && std::numeric_limits<UnsignedInt>::is_specialized
+                           && std::numeric_limits<UnsignedInt>::is_integer
+                           && !std::numeric_limits<UnsignedInt>::is_signed);
+   public:
+      /* details here */
+   };
+
+[endsect]
+
+[section:templates Use in templates]
+
+Normally static assertions when used inside a class or function template, 
+will not be instantiated until the template in which it is used is instantiated.  
+However, there is one potential problem to watch out for: if the static assertion 
+is not dependent upon one or more template parameters, then the compiler is 
+permitted to evaluate the static assertion at the point it is first seen, 
+irrespective of whether the template is ever instantiated, for example:
+
+   template <class T>
+   struct must_not_be_instantiated
+   {   
+      BOOST_STATIC_ASSERT(false);
+   };
+
+Will produce a compiler error with some compilers (for example Intel 8.1 
+or gcc 3.4), regardless of whether the template is ever instantiated.  A 
+workaround in cases like this is to force the assertion to be dependent 
+upon a template parameter:
+
+   template <class T>
+   struct must_not_be_instantiated
+   {   
+      // this will be triggered if this type is instantiated
+      BOOST_STATIC_ASSERT(sizeof(T) == 0); 
+   };
+
+
+[endsect]
+
+[endsect]
+
+[section:how How it works]
+
+`BOOST_STATIC_ASSERT` works as follows. There is class `STATIC_ASSERTION_FAILURE`
+ which is defined as:
+
+   namespace boost{
+
+   template <bool> struct STATIC_ASSERTION_FAILURE;
+
+   template <> struct STATIC_ASSERTION_FAILURE<true>{};
+
+   }
+
+The key feature is that the error message triggered by the undefined 
+expression `sizeof(STATIC_ASSERTION_FAILURE<0>)`, tends to be consistent 
+across a wide variety of compilers. The rest of the machinery of 
+`BOOST_STATIC_ASSERT` is just a way to feed the `sizeof` expression into a `typedef`. 
+The use of a macro here is somewhat ugly; however boost members have spent 
+considerable effort trying to invent a static assert that avoided macros, 
+all to no avail. The general conclusion was that the good of a static assert 
+working at namespace, function, and class scope outweighed the ugliness of a macro.
+
+[endsect]
+
+[section:test Test Programs]
+
+[table Test programs provided with static_assert
+[[Test Program][Expected to Compile][Description]]
+
+[[[@../../libs/static_assert/static_assert_test.cpp static_assert_test.cpp]] [Yes] [Illustrates usage, and should always compile, really just tests compiler compatibility.]] 
+[[[@../../libs/static_assert/static_assert_example_1.cpp static_assert_example_1.cpp]] [Platform dependent.] [Namespace scope test program, may compile depending upon the platform. ]]
+[[[@../../libs/static_assert/static_assert_example_2.cpp static_assert_example_2.cpp]] [Yes] [Function scope test program. ]]
+[[[@../../libs/static_assert/static_assert_example_3.cpp static_assert_example_3.cpp]] [Yes] [Class scope test program. ]]
+[[[@../../libs/static_assert/static_assert_test_fail_1.cpp static_assert_test_fail_1.cpp]] [No] [Illustrates failure at namespace scope. ]]
+[[[@../../libs/static_assert/static_assert_test_fail_2.cpp static_assert_test_fail_2.cpp]] [No] [Illustrates failure at non-template function scope. ]]
+[[[@../../libs/static_assert/static_assert_test_fail_3.cpp static_assert_test_fail_3.cpp]] [No] [Illustrates failure at non-template class scope. ]]
+[[[@../../libs/static_assert/static_assert_test_fail_4.cpp static_assert_test_fail_4.cpp]] [No] [Illustrates failure at non-template class scope. ]]
+[[[@../../libs/static_assert/static_assert_test_fail_5.cpp static_assert_test_fail_5.cpp]] [No] [Illustrates failure at template class scope. ]]
+[[[@../../libs/static_assert/static_assert_test_fail_6.cpp static_assert_test_fail_6.cpp]] [No] [Illustrates failure at template class member function scope. ]]
+[[[@../../libs/static_assert/static_assert_test_fail_7.cpp static_assert_test_fail_7.cpp]] [No] [Illustrates failure of class scope example. ]]
+[[[@../../libs/static_assert/static_assert_test_fail_8.cpp static_assert_test_fail_8.cpp]] [No] [Illustrates failure of function scope example. ]]
+[[[@../../libs/static_assert/static_assert_test_fail_9.cpp static_assert_test_fail_9.cpp]] [No] [Illustrates failure of function scope example (part 2). ]]
+
+]
+
+[endsect]
+
+

include/boost/static_assert.hpp

@@ -1,21 +1,21 @@
 //  (C) Copyright John Maddock 2000.
-//  Permission to copy, use, modify, sell and
+//  Use, modification and distribution are subject to the 
-//  distribute this software is granted provided this copyright notice appears
+//  Boost Software License, Version 1.0. (See accompanying file 
-//  in all copies. This software is provided "as is" without express or implied
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-//  warranty, and with no claim as to its suitability for any purpose.
 
-//  See http://www.boost.org for most recent version including documentation.
+//  See http://www.boost.org/libs/static_assert for documentation.
 
 /*
  Revision history:
- 	02 August 2000
+   02 August 2000
- 		Initial version.
+      Initial version.
 */
 
 #ifndef BOOST_STATIC_ASSERT_HPP
 #define BOOST_STATIC_ASSERT_HPP
 
 #include <boost/config.hpp>
+#include <boost/detail/workaround.hpp>
 
 #ifdef __BORLANDC__
 //
@@ -23,12 +23,31 @@
 #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)))
+#  define BOOST_STATIC_ASSERT_BOOL_CAST( x ) ((x) == 0 ? false : true)
+#else
+#  define BOOST_STATIC_ASSERT_BOOL_CAST(x) (bool)(x)
+#endif
+
+#ifdef BOOST_HAS_STATIC_ASSERT
+#  define BOOST_STATIC_ASSERT( B ) static_assert(B, #B)
+#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>{};
+template <> struct STATIC_ASSERTION_FAILURE<true> { enum { value = 1 }; };
 
 // HP aCC cannot deal with missing names for template value parameters
 template<int x> struct static_assert_test{};
@@ -57,30 +76,57 @@ template<int x> struct static_assert_test{};
 // 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__)
+#if !defined(BOOST_BUGGY_INTEGRAL_CONSTANT_EXPRESSIONS)
-#ifndef BOOST_MSVC
+
-#define BOOST_STATIC_ASSERT( B ) \
+#if defined(BOOST_MSVC) && (BOOST_MSVC < 1300)
-   typedef ::boost::static_assert_test<\
-      sizeof(::boost::STATIC_ASSERTION_FAILURE< (bool)( B ) >)>\
-         BOOST_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_
+#elif defined(BOOST_MSVC)
+#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_INTEL_CXX_VERSION) || defined(BOOST_SA_GCC_WORKAROUND)
+// 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(__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
+#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__)
 #endif
+
 #else
 // alternative enum based implementation:
 #define BOOST_STATIC_ASSERT( B ) \
    enum { BOOST_JOIN(boost_static_assert_enum_, __LINE__) \
       = sizeof(::boost::STATIC_ASSERTION_FAILURE< (bool)( B ) >) }
 #endif
-
+#endif // ndef BOOST_HAS_STATIC_ASSERT
 
 #endif // BOOST_STATIC_ASSERT_HPP
 
 
-
-

index.html

@@ -0,0 +1,18 @@
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
+<html>
+  <head>
+    <meta http-equiv="refresh" content="0; URL=../../doc/html/boost_staticassert.html">
+  </head>
+  <body>
+    Automatic redirection failed, please go to
+    <a href="../../doc/html/boost_staticassert.html">../../doc/html/boost_staticassert.html</a>
+    or view the online version at 
+    <a href="http://www.boost.org/regression-logs/cs-win32_metacomm/doc/html/boost_staticassert.html">
+    http://www.boost.org/regression-logs/cs-win32_metacomm/doc/html/boost_staticassert.html</a>
+      <P>Copyright&nbsp;John Maddock 2006</P>
+      <P>Distributed under the Boost Software License, Version 1.0. (See accompanying file <A href="../../LICENSE_1_0.txt">
+            LICENSE_1_0.txt</A> or copy at <A href="http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</A>).</P>
+  </body>
+</html>
+
+

static_assert.htm

@@ -1,279 +1,18 @@
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
 <html>
-
+  <head>
-<head>
+    <meta http-equiv="refresh" content="0; URL=../../doc/html/boost_staticassert.html">
-<meta http-equiv="Content-Type"
+  </head>
-content="text/html; charset=iso-8859-1">
+  <body>
-<meta name="Template"
+    Automatic redirection failed, please go to
-content="C:\PROGRAM FILES\MICROSOFT OFFICE\OFFICE\html.dot">
+    <a href="../../doc/html/boost_staticassert.html">../../doc/html/boost_staticassert.html</a>
-<meta name="GENERATOR" content="Microsoft FrontPage Express 2.0">
+    or view the online version at 
-<title>static assertions</title>
+    <a href="http://www.boost.org/regression-logs/cs-win32_metacomm/doc/html/boost_staticassert.html">
-</head>
+    http://www.boost.org/regression-logs/cs-win32_metacomm/doc/html/boost_staticassert.html</a>
-
+      <P>Copyright&nbsp;John Maddock 2006</P>
-<body bgcolor="#FFFFFF" text="#000000" link="#0000FF"
+      <P>Distributed under the Boost Software License, Version 1.0. (See accompanying file <A href="../../LICENSE_1_0.txt">
-vlink="#800080">
+            LICENSE_1_0.txt</A> or copy at <A href="http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</A>).</P>
-
+  </body>
-<h1><img src="../../c++boost.gif" width="276" height="86">Header
-&lt;<a href="../../boost/static_assert.hpp">boost/static_assert.hpp</a>&gt;</h1>
-
-<p>The header &lt;boost/static_assert.hpp&gt; supplies a single
-macro BOOST_STATIC_ASSERT(x), which generates a compile time
-error message if the <a
-href="../../more/int_const_guidelines.htm">integral-constant-expression</a>
-<i>x</i> is not true. In other words it is the compile time
-equivalent of the assert macro; this is sometimes known as a
-&quot;compile-time-assertion&quot;, but will be called a &quot;static
-assertion&quot; throughout these docs. Note that if the condition
-is true, then the macro will generate neither code nor data - and
-the macro can also be used at either namespace, class or function
-scope. When used in a template, the static assertion will be
-evaluated at the time the template is instantiated; this is
-particularly useful for validating template parameters. </p>
-
-<p>One of the aims of BOOST_STATIC_ASSERT is to generate readable
-error messages. These immediately tell the user that a library is
-being used in a manner that is not supported. While error
-messages obviously differ from compiler to compiler, but you
-should see something like: </p>
-
-<pre>Illegal use of COMPILE_TIME_ASSERTION_FAILURE&lt;false&gt;</pre>
-
-<p>Which is intended to at least catch the eye!</p>
-
-<p>You can use BOOST_STATIC_ASSERT at any place where you can
-place a declaration, that is at <a href="#class">class</a>, <a
-href="#function">function</a> or <a href="#namespace">namespace</a>
-scope, this is illustrated by the following examples:</p>
-
-<h3><a name="namespace"></a>Use at namespace scope.</h3>
-
-<p>The macro can be used at namespace scope, if there is some
-requirement must always be true; generally this means some
-platform specific requirement. Suppose we require that <b>int</b>
-be at least a 32-bit integral type, and that <b>wchar_t</b> be an
-unsigned type. We can verify this at compile time as follows:</p>
-
-<pre>#include &lt;climits&gt;
-#include &lt;cwchar&gt;
-#include &lt;boost/static_assert.hpp&gt;
-
-namespace my_conditions {
-
-BOOST_STATIC_ASSERT(sizeof(int) * CHAR_BIT &gt;= 32);
-BOOST_STATIC_ASSERT(WCHAR_MIN &gt;= 0);
-
-} // namespace my_conditions
-</pre>
-
-<p>The use of the namespace <i>my_conditions</i> here requires
-some comment. The macro BOOST_STATIC_ASSERT works by generating
-an <strong>typedef</strong> declaration, and since the typedef
-must have a name, the macro generates one automatically by
-mangling a stub name with the value of __LINE__. When
-BOOST_STATIC_ASSERT is used at either class or function scope
-then each use of BOOST_STATIC_ASSERT is guaranteed to produce a
-name unique to that scope (provided you only use the macro once
-on each line). However when used in a header at namespace scope,
-that namespace can be continued over multiple headers, each of
-which may have their own static assertions, and on the &quot;same&quot;
-lines, thereby generating duplicate declarations. In theory the
-compiler should silently ignore duplicate typedef declarations,
-however many do not do so (and even if they do they are entitled
-to emit warnings in such cases). To avoid potential problems, if
-you use BOOST_STATIC_ASSERT in a header and at namespace scope,
-then enclose them in a namespace unique to that header.</p>
-
-<h3><a name="function"></a>Use at function scope</h3>
-
-<p>The macro is typically used at function scope inside template
-functions, when the template arguments need checking. Imagine
-that we have an iterator-based algorithm that requires random
-access iterators. If the algorithm is instantiated with iterators
-that do not meet our requirements then an error will be generated
-eventually, but this may be nested deep inside several templates,
-making it hard for the user to determine what went wrong. One
-option is to add a static assertion at the top level of the
-template, in that case if the condition is not met, then an error
-will be generated in a way that makes it reasonably obvious to
-the user that the template is being misused.</p>
-
-<pre>#include &lt;iterator&gt;
-#include &lt;boost/static_assert.hpp&gt;
-#include &lt;boost/type_traits.hpp&gt;
-
-template &lt;class RandomAccessIterator &gt;
-RandomAccessIterator foo(RandomAccessIterator from, RandomAccessIterator to)
-{
-   // this template can only be used with
-   // random access iterators...
-   typedef typename std::iterator_traits&lt; RandomAccessIterator &gt;::iterator_category cat;
-   BOOST_STATIC_ASSERT((boost::is_convertible&lt;cat, const std::random_access_iterator_tag&amp;&gt;::value));
-   //
-   // detail goes here...
-   return from;
-}</pre>
-
-<p>A couple of footnotes are in order here: the extra set of
-parenthesis around the assert, is to prevent the comma inside the
-is_convertible template being interpreted by the preprocessor as
-a macro argument separator; the target type for is_convertible is
-a reference type, as some compilers have problems using
-is_convertible when the conversion is via a user defined
-constructor (in any case there is no guarantee that the iterator
-tag classes are copy-constructible).</p>
-
-<h3><a name="class"></a>Use at class scope</h3>
-
-<p>The macro is typically used inside classes that are templates.
-Suppose we have a template-class that requires an unsigned
-integral type with at least 16-bits of precision as a template
-argument, we can achieve this using something like this:</p>
-
-<pre>#include &lt;climits&gt;
-#include &lt;boost/static_assert.hpp&gt;
-
-Template &lt;class UnsignedInt&gt;template &lt;class UnsignedInt&gt;
-class myclass
-{
-private:
-   BOOST_STATIC_ASSERT(sizeof(UnsignedInt) * CHAR_BIT &gt;= 16);
-   BOOST_STATIC_ASSERT(std::numeric_limits&lt;UnsignedInt&gt;::is_specialized
-                        &amp;&amp; std::numeric_limits&lt;UnsignedInt&gt;::is_integer
-                        &amp;&amp; !std::numeric_limits&lt;UnsignedInt&gt;::is_signed);
-public:
-   /* details here */
-};
-</pre>
-
-<h3>How it works</h3>
-
-<p>BOOST_STATIC_ASSERT works as follows. There is class
-STATIC_ASSERTION_FAILURE which is defined as:</p>
-
-<pre>namespace boost{
-
-template &lt;bool&gt; struct STATIC_ASSERTION_FAILURE;
-
-template &lt;&gt; struct STATIC_ASSERTION_FAILURE&lt;true&gt;{};
-
-}</pre>
-
-<p>The key feature is that the error message triggered by the
-undefined expression sizeof(STATIC_ASSERTION_FAILURE&lt;0&gt;),
-tends to be consistent across a wide variety of compilers. The
-rest of the machinery of BOOST_STATIC_ASSERT is just a way to
-feed the sizeof expression into a typedef. The use of a macro
-here is somewhat ugly; however boost members have spent
-considerable effort trying to invent a static assert that avoided
-macros, all to no avail. The general conclusion was that the good
-of a static assert working at namespace, function, and class
-scope outweighed the ugliness of a macro.</p>
-
-<h3>Test Programs</h3>
-
-<p>The following test programs are provided with this library:</p>
-
-<table border="0" width="100%">
-    <tr>
-        <td width="33%"><i>Test Program</i></td>
-        <td width="33%"><i>Expected to Compile</i></td>
-        <td width="34%"><i>Description</i></td>
-    </tr>
-    <tr>
-        <td width="33%"><a href="static_assert_test.cpp">static_assert_test.cpp</a></td>
-        <td width="33%">Yes</td>
-        <td width="34%">Illustrates usage, and should always
-        compile, really just tests compiler compatibility.</td>
-    </tr>
-    <tr>
-        <td width="33%"><a href="static_assert_example_1.cpp">static_assert_example_1.cpp</a></td>
-        <td width="33%">Platform dependent.</td>
-        <td width="34%">Namespace scope test program, may compile
-        depending upon the platform.</td>
-    </tr>
-    <tr>
-        <td width="33%"><a href="static_assert_example_2.cpp">static_assert_example_2.cpp</a></td>
-        <td width="33%">Yes</td>
-        <td width="34%">Function scope test program.</td>
-    </tr>
-    <tr>
-        <td width="33%"><a href="static_assert_example_3.cpp">static_assert_example_3.cpp</a></td>
-        <td width="33%">Yes</td>
-        <td width="34%">Class scope test program.</td>
-    </tr>
-    <tr>
-        <td width="33%"><a href="static_assert_test_fail_1.cpp">static_assert_test_fail_1.cpp</a></td>
-        <td width="33%">No</td>
-        <td width="34%">Illustrates failure at namespace scope.</td>
-    </tr>
-    <tr>
-        <td width="33%"><a href="static_assert_test_fail_2.cpp">static_assert_test_fail_2.cpp</a></td>
-        <td width="33%">No</td>
-        <td width="34%">Illustrates failure at non-template
-        function scope.</td>
-    </tr>
-    <tr>
-        <td width="33%"><a href="static_assert_test_fail_3.cpp">static_assert_test_fail_3.cpp</a></td>
-        <td width="33%">No</td>
-        <td width="34%">Illustrates failure at non-template class
-        scope.</td>
-    </tr>
-    <tr>
-        <td width="33%"><a href="static_assert_test_fail_4.cpp">static_assert_test_fail_4.cpp</a></td>
-        <td width="33%">No</td>
-        <td width="34%">Illustrates failure at non-template class
-        scope.</td>
-    </tr>
-    <tr>
-        <td width="33%"><a href="static_assert_test_fail_5.cpp">static_assert_test_fail_5.cpp</a></td>
-        <td width="33%">No</td>
-        <td width="34%">Illustrates failure at template class
-        scope.</td>
-    </tr>
-    <tr>
-        <td width="33%"><a href="static_assert_test_fail_6.cpp">static_assert_test_fail_6.cpp</a></td>
-        <td width="33%">No</td>
-        <td width="34%">Illustrates failure at template class
-        member function scope.</td>
-    </tr>
-    <tr>
-        <td width="33%"><a href="static_assert_test_fail_7.cpp">static_assert_test_fail_7.cpp</a></td>
-        <td width="33%">No</td>
-        <td width="34%">Illustrates failure of class scope
-        example.</td>
-    </tr>
-    <tr>
-        <td><a href="static_assert_test_fail_8.cpp">static_assert_test_fail_8.cpp</a></td>
-        <td>No</td>
-        <td>Illustrates failure of function scope example.</td>
-    </tr>
-    <tr>
-        <td><a href="static_assert_test_fail_9.cpp">static_assert_test_fail_9.cpp</a></td>
-        <td>No</td>
-        <td>Illustrates failure of function scope example (part 2).</td>
-    </tr>
-</table>
-
-<hr>
-
-<p>Revised 27th Nov 2000</p>
-
-<p>Documentation <20> Copyright John Maddock 2000. Permission to
-copy, use, modify, sell and distribute this document is granted
-provided this copyright notice appears in all copies. This
-document is provided &quot;as is&quot; without express or implied
-warranty, and with no claim as to its suitability for any purpose.</p>
-
-<p>Based on contributions by Steve Cleary and John Maddock.</p>
-
-<p>Maintained by <a href="mailto:John_Maddock@compuserve.com">John
-Maddock</a>, the latest version of this file can be found at <a
-href="http://www.boost.org/">www.boost.org</a>, and the boost
-discussion list at <a
-href="http://www.yahoogroups.com/list/boost">www.yahoogroups.com/list/boost</a>.
-</p>
-
-<p>&nbsp;</p>
-
-<p>&nbsp;</p>
-</body>
 </html>
+
+

static_assert_example_1.cpp

@@ -1,23 +1,23 @@
 //  (C) Copyright Steve Cleary & John Maddock 2000.
-//  Permission to copy, use, modify, sell and
+//  Use, modification and distribution are subject to the 
-//  distribute this software is granted provided this copyright notice appears
+//  Boost Software License, Version 1.0. (See accompanying file 
-//  in all copies. This software is provided "as is" without express or implied
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-//  warranty, and with no claim as to its suitability for any purpose.
 
 //  See http://www.boost.org for most recent version including documentation.
 
 #include <climits>
 #include <cwchar>
+#include <limits>
 #include <boost/static_assert.hpp>
 
-#if defined(__BORLANDC__) && !defined(WCHAR_MIN)
+#if !defined(WCHAR_MIN)
 #define WCHAR_MIN 0
 #endif
 
 namespace boost{
 
 namespace my_conditions {
-BOOST_STATIC_ASSERT(sizeof(int) * CHAR_BIT >= 32);
+BOOST_STATIC_ASSERT(std::numeric_limits<int>::digits >= 32);
 BOOST_STATIC_ASSERT(WCHAR_MIN >= 0);
 
 } // namespace my_conditions
@@ -29,3 +29,6 @@ int main()
    return 0;
 }
 
+
+
+

static_assert_example_2.cpp

@@ -1,8 +1,7 @@
 //  (C) Copyright John Maddock 2000.
-//  Permission to copy, use, modify, sell and
+//  Use, modification and distribution are subject to the 
-//  distribute this software is granted provided this copyright notice appears
+//  Boost Software License, Version 1.0. (See accompanying file 
-//  in all copies. This software is provided "as is" without express or implied
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-//  warranty, and with no claim as to its suitability for any purpose.
 
 //  See http://www.boost.org for most recent version including documentation.
 
@@ -26,11 +25,11 @@ RandomAccessIterator foo(RandomAccessIterator from, RandomAccessIterator to)
 
 int main()
 {
-	std::deque<int> d;
+   std::deque<int> d;
-	std::list<int> l;
+   std::list<int> l;
-	foo(d.begin(), d.end()); // OK
+   foo(d.begin(), d.end()); // OK
-	//foo(l.begin(), l.end()); // error
+   //foo(l.begin(), l.end()); // error
-	return 0;
+   return 0;
 }
 
 
@@ -38,3 +37,4 @@ int main()
 
 
 
+

static_assert_example_3.cpp

@@ -1,8 +1,7 @@
 //  (C) Copyright John Maddock 2000.
-//  Permission to copy, use, modify, sell and
+//  Use, modification and distribution are subject to the 
-//  distribute this software is granted provided this copyright notice appears
+//  Boost Software License, Version 1.0. (See accompanying file 
-//  in all copies. This software is provided "as is" without express or implied
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-//  warranty, and with no claim as to its suitability for any purpose.
 
 //  See http://www.boost.org for most recent version including documentation.
 
@@ -14,8 +13,8 @@ template <class UnsignedInt>
 class myclass
 {
 private:
-   BOOST_STATIC_ASSERT(sizeof(UnsignedInt) * CHAR_BIT >= 16);
+   BOOST_STATIC_ASSERT((std::numeric_limits<UnsignedInt>::digits >= 16)
-   BOOST_STATIC_ASSERT(std::numeric_limits<UnsignedInt>::is_specialized
+                        && std::numeric_limits<UnsignedInt>::is_specialized
                         && std::numeric_limits<UnsignedInt>::is_integer
                         && !std::numeric_limits<UnsignedInt>::is_signed);
 public:
@@ -30,3 +29,5 @@ int main()
 {
    return 0;
 }
+
+

static_assert_test.cpp

@@ -1,8 +1,7 @@
 //  (C) Copyright Steve Cleary & John Maddock 2000.
-//  Permission to copy, use, modify, sell and
+//  Use, modification and distribution are subject to the 
-//  distribute this software is granted provided this copyright notice appears
+//  Boost Software License, Version 1.0. (See accompanying file 
-//  in all copies. This software is provided "as is" without express or implied
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-//  warranty, and with no claim as to its suitability for any purpose.
 
 //  See http://www.boost.org for most recent version including documentation.
 
@@ -84,3 +83,4 @@ int main()
 
 
 
+

static_assert_test_fail_1.cpp

@@ -1,8 +1,7 @@
 //  (C) Copyright Steve Cleary & John Maddock 2000.
-//  Permission to copy, use, modify, sell and
+//  Use, modification and distribution are subject to the 
-//  distribute this software is granted provided this copyright notice appears
+//  Boost Software License, Version 1.0. (See accompanying file 
-//  in all copies. This software is provided "as is" without express or implied
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-//  warranty, and with no claim as to its suitability for any purpose.
 
 //  See http://www.boost.org for most recent version including documentation.
 
@@ -11,9 +10,12 @@
 //
 // all these tests should fail:
 //
+typedef char a1[2];
+typedef char a2[3];
 
 // Namespace scope
-BOOST_STATIC_ASSERT(sizeof(int) == sizeof(char)); // will not compile
+BOOST_STATIC_ASSERT(sizeof(a1) == sizeof(a2)); // will not compile
+
 
 
 

static_assert_test_fail_10.cpp

@@ -0,0 +1,18 @@
+//~ Copyright 2005 Redshift Software, Inc.
+//~ Distributed under the Boost Software License, Version 1.0.
+//~ (See accompanying file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
+
+#include <boost/static_assert.hpp>
+
+template <int N>
+int foo()
+{
+    BOOST_STATIC_ASSERT( N < 2 );
+    
+    return N;
+}
+
+int main()
+{
+    return foo<5>();
+}

static_assert_test_fail_2.cpp

@@ -1,8 +1,7 @@
 //  (C) Copyright Steve Cleary & John Maddock 2000.
-//  Permission to copy, use, modify, sell and
+//  Use, modification and distribution are subject to the 
-//  distribute this software is granted provided this copyright notice appears
+//  Boost Software License, Version 1.0. (See accompanying file 
-//  in all copies. This software is provided "as is" without express or implied
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-//  warranty, and with no claim as to its suitability for any purpose.
 
 //  See http://www.boost.org for most recent version including documentation.
 
@@ -11,13 +10,16 @@
 //
 // all these tests should fail:
 //
+typedef char a1[2];
+typedef char a2[3];
 
 // Function (block) scope
 void f()
 {
-  BOOST_STATIC_ASSERT(sizeof(int) == sizeof(char)); // should not compile
+  BOOST_STATIC_ASSERT(sizeof(a1) == sizeof(a2)); // should not compile
 }
 
 
 
 
+

static_assert_test_fail_3.cpp

@@ -1,8 +1,7 @@
 //  (C) Copyright Steve Cleary & John Maddock 2000.
-//  Permission to copy, use, modify, sell and
+//  Use, modification and distribution are subject to the 
-//  distribute this software is granted provided this copyright notice appears
+//  Boost Software License, Version 1.0. (See accompanying file 
-//  in all copies. This software is provided "as is" without express or implied
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-//  warranty, and with no claim as to its suitability for any purpose.
 
 //  See http://www.boost.org for most recent version including documentation.
 
@@ -11,11 +10,13 @@
 //
 // this tests should fail:
 //
+typedef char a1[2];
+typedef char a2[3];
 
 struct Bob
 {
   private:  // can be in private, to avoid namespace pollution
-    BOOST_STATIC_ASSERT(sizeof(int) == sizeof(char)); // will not compile
+    BOOST_STATIC_ASSERT(sizeof(a1) == sizeof(a2)); // will not compile
   public:
 
   // Member function scope: provides access to member variables
@@ -27,7 +28,6 @@ struct Bob
     BOOST_STATIC_ASSERT(sizeof(x) == 4);
     BOOST_STATIC_ASSERT(sizeof(c) == 1);
 #endif
-    //BOOST_STATIC_ASSERT((sizeof(x) == sizeof(c))); // should not compile
     return x;
   }
 };
@@ -36,3 +36,4 @@ struct Bob
 
 
 
+

static_assert_test_fail_4.cpp

@@ -1,8 +1,7 @@
 //  (C) Copyright Steve Cleary & John Maddock 2000.
-//  Permission to copy, use, modify, sell and
+//  Use, modification and distribution are subject to the 
-//  distribute this software is granted provided this copyright notice appears
+//  Boost Software License, Version 1.0. (See accompanying file 
-//  in all copies. This software is provided "as is" without express or implied
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-//  warranty, and with no claim as to its suitability for any purpose.
 
 //  See http://www.boost.org for most recent version including documentation.
 
@@ -19,11 +18,11 @@ struct Bob
   public:
 
   // Member function scope: provides access to member variables
-  int x;
+  char x[4];
   char c;
   int f()
   {
-#ifndef BOOST_MSVC // broken sizeof in VC6
+#if !defined(BOOST_MSVC) || BOOST_MSVC > 1200 // broken sizeof in VC6
     BOOST_STATIC_ASSERT(sizeof(x) == 4);
     BOOST_STATIC_ASSERT(sizeof(c) == 1);
     BOOST_STATIC_ASSERT((sizeof(x) == sizeof(c))); // should not compile
@@ -36,3 +35,4 @@ struct Bob
 
 
 
+

static_assert_test_fail_5.cpp

@@ -1,8 +1,7 @@
 //  (C) Copyright Steve Cleary & John Maddock 2000.
-//  Permission to copy, use, modify, sell and
+//  Use, modification and distribution are subject to the 
-//  distribute this software is granted provided this copyright notice appears
+//  Boost Software License, Version 1.0. (See accompanying file 
-//  in all copies. This software is provided "as is" without express or implied
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-//  warranty, and with no claim as to its suitability for any purpose.
 
 //  See http://www.boost.org for most recent version including documentation.
 
@@ -37,3 +36,4 @@ Bill<int, char> b;
 
 
 
+

static_assert_test_fail_6.cpp

@@ -1,8 +1,7 @@
 //  (C) Copyright Steve Cleary & John Maddock 2000.
-//  Permission to copy, use, modify, sell and
+//  Use, modification and distribution are subject to the 
-//  distribute this software is granted provided this copyright notice appears
+//  Boost Software License, Version 1.0. (See accompanying file 
-//  in all copies. This software is provided "as is" without express or implied
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-//  warranty, and with no claim as to its suitability for any purpose.
 
 //  See http://www.boost.org for most recent version including documentation.
 
@@ -44,3 +43,4 @@ void foo()
 
 
 
+

static_assert_test_fail_7.cpp

@@ -1,8 +1,7 @@
 //  (C) Copyright John Maddock 2000.
-//  Permission to copy, use, modify, sell and
+//  Use, modification and distribution are subject to the 
-//  distribute this software is granted provided this copyright notice appears
+//  Boost Software License, Version 1.0. (See accompanying file 
-//  in all copies. This software is provided "as is" without express or implied
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-//  warranty, and with no claim as to its suitability for any purpose.
 
 //  See http://www.boost.org for most recent version including documentation.
 
@@ -29,3 +28,4 @@ int main()
 {
    return 0;
 }
+

static_assert_test_fail_8.cpp

@@ -1,8 +1,7 @@
 //  (C) Copyright John Maddock 2000.
-//  Permission to copy, use, modify, sell and
+//  Use, modification and distribution are subject to the 
-//  distribute this software is granted provided this copyright notice appears
+//  Boost Software License, Version 1.0. (See accompanying file 
-//  in all copies. This software is provided "as is" without express or implied
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-//  warranty, and with no claim as to its suitability for any purpose.
 
 //  See http://www.boost.org for most recent version including documentation.
 
@@ -12,27 +11,34 @@
 #include <boost/static_assert.hpp>
 #include <boost/type_traits.hpp>
 
-template <class RandonAccessIterator >
+template <class RandomAccessIterator >
-RandonAccessIterator foo(RandonAccessIterator from, RandonAccessIterator to)
+RandomAccessIterator foo(RandomAccessIterator from, RandomAccessIterator)
 {
    // this template can only be used with
    // random access iterators...
-   typedef typename std::iterator_traits< RandonAccessIterator >::iterator_category cat;
+   typedef typename std::iterator_traits< RandomAccessIterator >::iterator_category cat;
    BOOST_STATIC_ASSERT((boost::is_convertible<cat*, std::random_access_iterator_tag*>::value));
    //
    // detail goes here...
    return from;
 }
 
+// ensure that delayed instantiation compilers like Comeau see the failure early
+// enough for "compile-fail" testing with the Boost.Build testing framework. (Greg Comeau)
+template
+std::list<int>::iterator
+   foo(std::list<int>::iterator, std::list<int>::iterator);
+
 int main()
 {
-	std::deque<int> d;
+   std::deque<int> d;
-	std::list<int> l;
+   std::list<int> l;
-	foo(d.begin(), d.end()); // OK
+   foo(d.begin(), d.end()); // OK
-	foo(l.begin(), l.end()); // error
+   foo(l.begin(), l.end()); // error
-	return 0;
+   return 0;
 }
 
 
  
 
+

static_assert_test_fail_9.cpp

@@ -1,8 +1,7 @@
 //  (C) Copyright John Maddock 2000.
-//  Permission to copy, use, modify, sell and
+//  Use, modification and distribution are subject to the 
-//  distribute this software is granted provided this copyright notice appears
+//  Boost Software License, Version 1.0. (See accompanying file 
-//  in all copies. This software is provided "as is" without express or implied
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-//  warranty, and with no claim as to its suitability for any purpose.
 
 //  See http://www.boost.org for most recent version including documentation.
 
@@ -30,3 +29,4 @@ int main()
 {
    return 0;
 }
+