Use C++11 static_assert() if available.

src/checks.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 212 matching lines @@
 #define CHECK_NE(unexpected, value) CheckNonEqualsHelper(__FILE__, __LINE__, \
   #unexpected, unexpected, #value, value)
 
 
 #define CHECK_GT(a, b) CHECK((a) > (b))
 #define CHECK_GE(a, b) CHECK((a) >= (b))
 #define CHECK_LT(a, b) CHECK((a) < (b))
 #define CHECK_LE(a, b) CHECK((a) <= (b))
 
 
+// Use C++11 static_assert if possible, which gives error
+// messages that are easier to understand on first sight.
+#if __cplusplus >= 201103L || \
+    (defined(__has_feature) && __has_feature(cxx_static_assert)) || \
+    (defined(__has_extension) && __has_extension(cxx_static_assert))

[Sven Panne, 2013/07/18 06:45:30]

autoconf by hand? ;-)

+#define STATIC_CHECK(test) static_assert(test, #test)
+#else
 // This is inspired by the static assertion facility in boost.  This
 // is pretty magical.  If it causes you trouble on a platform you may
 // find a fix in the boost code.
 template <bool> class StaticAssertion;
 template <> class StaticAssertion<true> { };
 // This macro joins two tokens.  If one of the tokens is a macro the
 // helper call causes it to be resolved before joining.
 #define SEMI_STATIC_JOIN(a, b) SEMI_STATIC_JOIN_HELPER(a, b)
 #define SEMI_STATIC_JOIN_HELPER(a, b) a##b
 // Causes an error during compilation of the condition is not
 // statically known to be true.  It is formulated as a typedef so that
 // it can be used wherever a typedef can be used.  Beware that this
 // actually causes each use to introduce a new defined type with a
 // name depending on the source line.
 template <int> class StaticAssertionHelper { };
 #define STATIC_CHECK(test)                                                    \
   typedef                                                                     \
     StaticAssertionHelper<sizeof(StaticAssertion<static_cast<bool>((test))>)> \
     SEMI_STATIC_JOIN(__StaticAssertTypedef__, __LINE__)
+#endif
 
 
 extern bool FLAG_enable_slow_asserts;
 
 
 // The ASSERT macro is equivalent to CHECK except that it only
 // generates code in debug builds.
 #ifdef DEBUG
 #define ASSERT_RESULT(expr)    CHECK(expr)
 #define ASSERT(condition)      CHECK(condition)
@@ skipping 24 matching lines @@
 
 // "Extra checks" are lightweight checks that are enabled in some release
 // builds.
 #ifdef ENABLE_EXTRA_CHECKS
 #define EXTRA_CHECK(condition) CHECK(condition)
 #else
 #define EXTRA_CHECK(condition) ((void) 0)
 #endif
 
 #endif  // V8_CHECKS_H_