add boost on mac

macx64/include/boost/serialization/singleton.hpp

@@ -0,0 +1,218 @@
+#ifndef BOOST_SERIALIZATION_SINGLETON_HPP
+#define BOOST_SERIALIZATION_SINGLETON_HPP
+
+/////////1/////////2///////// 3/////////4/////////5/////////6/////////7/////////8
+//  singleton.hpp
+//
+// Copyright David Abrahams 2006. Original version
+//
+// Copyright Robert Ramey 2007.  Changes made to permit
+// application throughout the serialization library.
+//
+// Copyright Alexander Grund 2018. Corrections to singleton lifetime
+//
+// Distributed under 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)
+//
+// The intention here is to define a template which will convert
+// any class into a singleton with the following features:
+//
+// a) initialized before first use.
+// b) thread-safe for const access to the class
+// c) non-locking
+//
+// In order to do this,
+// a) Initialize dynamically when used.
+// b) Require that all singletons be initialized before main
+// is called or any entry point into the shared library is invoked.
+// This guarentees no race condition for initialization.
+// In debug mode, we assert that no non-const functions are called
+// after main is invoked.
+//
+
+// MS compatible compilers support #pragma once
+#if defined(_MSC_VER)
+# pragma once
+#endif
+
+#include <boost/assert.hpp>
+#include <boost/config.hpp>
+#include <boost/noncopyable.hpp>
+#include <boost/serialization/force_include.hpp>
+#include <boost/serialization/config.hpp>
+
+#include <boost/archive/detail/auto_link_archive.hpp>
+#include <boost/archive/detail/abi_prefix.hpp> // must be the last header
+
+#ifdef BOOST_MSVC
+#  pragma warning(push)
+#  pragma warning(disable : 4511 4512)
+#endif
+
+namespace boost {
+namespace serialization {
+
+//////////////////////////////////////////////////////////////////////
+// Provides a dynamically-initialized (singleton) instance of T in a
+// way that avoids LNK1179 on vc6.  See http://tinyurl.com/ljdp8 or
+// http://lists.boost.org/Archives/boost/2006/05/105286.php for
+// details.
+//
+
+// Singletons created by this code are guaranteed to be unique
+// within the executable or shared library which creates them.
+// This is sufficient and in fact ideal for the serialization library.
+// The singleton is created when the module is loaded and destroyed
+// when the module is unloaded.
+
+// This base class has two functions.
+
+// First it provides a module handle for each singleton indicating
+// the executable or shared library in which it was created. This
+// turns out to be necessary and sufficient to implement the tables
+// used by serialization library.
+
+// Second, it provides a mechanism to detect when a non-const function
+// is called after initialization.
+
+// Make a singleton to lock/unlock all singletons for alteration.
+// The intent is that all singletons created/used by this code
+// are to be initialized before main is called. A test program
+// can lock all the singletons when main is entered.  Thus any
+// attempt to retrieve a mutable instance while locked will
+// generate an assertion if compiled for debug.
+
+// The singleton template can be used in 2 ways:
+// 1 (Recommended): Publicly inherit your type T from singleton<T>,
+// make its ctor protected and access it via T::get_const_instance()
+// 2: Simply access singleton<T> without changing T. Note that this only
+// provides a global instance accesible by singleton<T>::get_const_instance()
+// or singleton<T>::get_mutable_instance() to prevent using multiple instances
+// of T make its ctor protected
+
+// Note on usage of BOOST_DLLEXPORT: These functions are in danger of
+// being eliminated by the optimizer when building an application in
+// release mode. Usage of the macro is meant to signal the compiler/linker
+// to avoid dropping these functions which seem to be unreferenced.
+// This usage is not related to autolinking.
+
+class BOOST_SYMBOL_VISIBLE singleton_module :
+    public boost::noncopyable
+{
+private:
+    BOOST_DLLEXPORT bool & get_lock() BOOST_USED {
+        static bool lock = false;
+        return lock;
+    }
+
+public:
+    BOOST_DLLEXPORT void lock(){
+        get_lock() = true;
+    }
+    BOOST_DLLEXPORT void unlock(){
+        get_lock() = false;
+    }
+    BOOST_DLLEXPORT bool is_locked(){
+        return get_lock();
+    }
+};
+
+static inline singleton_module & get_singleton_module(){
+    static singleton_module m;
+    return m;
+}
+
+namespace detail {
+
+// This is the class actually instantiated and hence the real singleton.
+// So there will only be one instance of this class. This does not hold
+// for singleton<T> as a class derived from singleton<T> could be
+// instantiated multiple times.
+// It also provides a flag `is_destroyed` which returns true, when the
+// class was destructed. It is static and hence accesible even after
+// destruction. This can be used to check, if the singleton is still
+// accesible e.g. in destructors of other singletons.
+template<class T>
+class singleton_wrapper : public T
+{
+    static bool & get_is_destroyed(){
+        // Prefer a static function member to avoid LNK1179.
+        // Note: As this is for a singleton (1 instance only) it must be set
+        // never be reset (to false)!
+        static bool is_destroyed_flag = false;
+        return is_destroyed_flag;
+    }
+public:
+    singleton_wrapper(){
+        BOOST_ASSERT(! is_destroyed());
+    }
+    ~singleton_wrapper(){
+        get_is_destroyed() = true;
+    }
+    static bool is_destroyed(){
+        return get_is_destroyed();
+    }
+};
+
+} // detail
+
+template <class T>
+class singleton {
+private:
+    static T * m_instance;
+    // include this to provoke instantiation at pre-execution time
+    static void use(T const &) {}
+    static T & get_instance() {
+        BOOST_ASSERT(! is_destroyed());
+
+        // use a wrapper so that types T with protected constructors can be used
+        // Using a static function member avoids LNK1179
+        static detail::singleton_wrapper< T > t;
+
+        // note that the following is absolutely essential.
+        // commenting out this statement will cause compilers to fail to
+        // construct the instance at pre-execution time.  This would prevent
+        // our usage/implementation of "locking" and introduce uncertainty into
+        // the sequence of object initialization.
+        // Unfortunately, this triggers detectors of undefine behavior
+        // and reports an error.  But I've been unable to find a different
+        // of guarenteeing that the the singleton is created at pre-main time.
+        use(* m_instance);
+
+        return static_cast<T &>(t);
+    }
+protected:
+    // Do not allow instantiation of a singleton<T>. But we want to allow
+    // `class T: public singleton<T>` so we can't delete this ctor
+    BOOST_DLLEXPORT singleton(){}
+
+public:
+    BOOST_DLLEXPORT static T & get_mutable_instance(){
+        BOOST_ASSERT(! get_singleton_module().is_locked());
+        return get_instance();
+    }
+    BOOST_DLLEXPORT static const T & get_const_instance(){
+        return get_instance();
+    }
+    BOOST_DLLEXPORT static bool is_destroyed(){
+        return detail::singleton_wrapper< T >::is_destroyed();
+    }
+};
+
+// Assigning the instance reference to a static member forces initialization
+// at startup time as described in
+// https://groups.google.com/forum/#!topic/microsoft.public.vc.language/kDVNLnIsfZk
+template<class T>
+T * singleton< T >::m_instance = & singleton< T >::get_instance();
+
+} // namespace serialization
+} // namespace boost
+
+#include <boost/archive/detail/abi_suffix.hpp> // pops abi_suffix.hpp pragmas
+
+#ifdef BOOST_MSVC
+#pragma warning(pop)
+#endif
+
+#endif // BOOST_SERIALIZATION_SINGLETON_HPP