wtf/StdLibExtras.h

   1 /*
   2  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #ifndef WTF_StdLibExtras_h
  27 #define WTF_StdLibExtras_h
  28
  29 #include <wtf/Platform.h>
  30 #include <wtf/Assertions.h>
  31
  32 // Use these to declare and define a static local variable (static T;) so that
  33 //  it is leaked so that its destructors are not called at exit. Using this
  34 //  macro also allows workarounds a compiler bug present in Apple's version of GCC 4.0.1.
  35 #if COMPILER(GCC) && defined(__APPLE_CC__) && __GNUC__ == 4 && __GNUC_MINOR__ == 0 && __GNUC_PATCHLEVEL__ == 1
  36 #define DEFINE_STATIC_LOCAL(type, name, arguments) \
  37     static type* name##Ptr = new type arguments; \
  38     type& name = *name##Ptr
  39 #else
  40 #define DEFINE_STATIC_LOCAL(type, name, arguments) \
  41     static type& name = *new type arguments
  42 #endif
  43
  44 namespace WTF {
  45
  46     /*
  47      * C++'s idea of a reinterpret_cast lacks sufficient cojones.
  48      */
  49     template<typename TO, typename FROM>
  50     TO bitwise_cast(FROM in)
  51     {
  52         COMPILE_ASSERT(sizeof(TO) == sizeof(FROM), WTF_wtf_reinterpret_cast_sizeof_types_is_equal);
  53         union {
  54             FROM from;
  55             TO to;
  56         } u;
  57         u.from = in;
  58         return u.to;
  59     }
  60
  61 } // namespace WTF
  62
  63 #endif