hphp/runtime/base/classname-is.h

   1 /*
   2    +----------------------------------------------------------------------+
   3    | HipHop for PHP                                                       |
   4    +----------------------------------------------------------------------+
   5    | Copyright (c) 2010-present Facebook, Inc. (http://www.facebook.com)  |
   6    | Copyright (c) 1997-2010 The PHP Group                                |
   7    +----------------------------------------------------------------------+
   8    | This source file is subject to version 3.01 of the PHP license,      |
   9    | that is bundled with this package in the file LICENSE, and is        |
  10    | available through the world-wide-web at the following url:           |
  11    | http://www.php.net/license/3_01.txt                                  |
  12    | If you did not receive a copy of the PHP license and are unable to   |
  13    | obtain it through the world-wide-web, please send a note to          |
  14    | license@php.net so we can mail you a copy immediately.               |
  15    +----------------------------------------------------------------------+
  16 */
  17
  18 #ifndef incl_HPHP_CLASSNAME_IS_H
  19 #define incl_HPHP_CLASSNAME_IS_H
  20
  21 namespace HPHP {
  22
  23 /**
  24  * InstantStatic allows defining a static in-class variable that is
  25  * initialized during program startup, without actually needing to define
  26  * it anywhere. When defining the static, just specify its type (T), the
  27  * type that T's constructor will receive (TInit), and the name of the
  28  * function that will be called for construction (init). One copy of
  29  * static data is generated per T/init.
  30  */
  31 template <typename T, typename TInit, TInit init()>
  32 struct InstantStatic {
  33   static T value;
  34 };
  35
  36 template <typename T, typename TInit, TInit init()>
  37 T InstantStatic<T, TInit, init>::value(init());
  38
  39 #define CLASSNAME_IS(str)                                               \
  40   static const auto& GetClassName() { return str; }                     \
  41   static const StaticString& classnameof() {                            \
  42     return InstantStatic<const StaticString,                            \
  43                          decltype(GetClassName()),                      \
  44                          GetClassName>::value;                          \
  45   }
  46
  47 #define RESOURCENAME_IS(str)                                            \
  48   static const auto& GetResourceName() { return str; }                  \
  49   static const StaticString& resourcenameof() {                         \
  50     return InstantStatic<const StaticString,                            \
  51                          decltype(GetResourceName()),                   \
  52                          GetResourceName>::value;                       \
  53   }
  54
  55 }
  56
  57 #endif