cereal
A C++11 library for serialization
static_object.hpp
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1 
4 /*
5  Copyright (c) 2014, Randolph Voorhies, Shane Grant
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28 #ifndef CEREAL_DETAILS_STATIC_OBJECT_HPP_
29 #define CEREAL_DETAILS_STATIC_OBJECT_HPP_
30 
31 #include "cereal/macros.hpp"
32 
33 #if CEREAL_THREAD_SAFE
34 #include <mutex>
35 #endif
36 
38 
47 #if defined(_MSC_VER) && !defined(__clang__)
48 # define CEREAL_DLL_EXPORT __declspec(dllexport)
49 # define CEREAL_USED
50 #else // clang or gcc
51 # define CEREAL_DLL_EXPORT __attribute__ ((visibility("default")))
52 # define CEREAL_USED __attribute__ ((__used__))
53 #endif
54 
55 namespace cereal
56 {
57  namespace detail
58  {
60 
66  template <class T>
68  {
69  private:
70 
71  static T & create()
72  {
73  static T t;
75  (void)instance;
76  return t;
77  }
78 
79  StaticObject( StaticObject const & /*other*/ ) {}
80 
81  public:
82  static T & getInstance()
83  {
84  return create();
85  }
86 
88  class LockGuard
89  {
90  #if CEREAL_THREAD_SAFE
91  public:
92  LockGuard(std::mutex & m) : lock(m) {}
93  private:
94  std::unique_lock<std::mutex> lock;
95  #else
96  public:
97  LockGuard() = default;
98  LockGuard(LockGuard const &) = default; // prevents implicit copy ctor warning
99  ~LockGuard() CEREAL_NOEXCEPT {} // prevents variable not used
100  #endif
101  };
102 
104 
110  static LockGuard lock()
111  {
112  #if CEREAL_THREAD_SAFE
113  static std::mutex instanceMutex;
114  return LockGuard{instanceMutex};
115  #else
116  return LockGuard{};
117  #endif
118  }
119 
120  private:
121  static T & instance;
122  };
123 
124  template <class T> T & StaticObject<T>::instance = StaticObject<T>::create();
125  } // namespace detail
126 } // namespace cereal
127 
128 #endif // CEREAL_DETAILS_STATIC_OBJECT_HPP_
cereal::detail::StaticObject::LockGuard
A class that acts like std::lock_guard.
Definition: static_object.hpp:88
macros.hpp
Preprocessor macros that can customise the cereal library.
CEREAL_DLL_EXPORT
#define CEREAL_DLL_EXPORT
Prevent link optimization from removing non-referenced static objects.
Definition: static_object.hpp:51
cereal::detail::StaticObject
A static, pre-execution object.
Definition: static_object.hpp:67
cereal::detail::StaticObject::lock
static LockGuard lock()
Attempts to lock this static object for the current scope.
Definition: static_object.hpp:110
CEREAL_NOEXCEPT
#define CEREAL_NOEXCEPT
Defines the CEREAL_NOEXCEPT macro to use instead of noexcept.
Definition: macros.hpp:130