Added boost header

test/external/boost/variant/detail/backup_holder.hpp

@@ -0,0 +1,94 @@
+//-----------------------------------------------------------------------------
+// boost variant/detail/backup_holder.hpp header file
+// See http://www.boost.org for updates, documentation, and revision history.
+//-----------------------------------------------------------------------------
+//
+// Copyright (c) 2003
+// Eric Friedman
+//
+// 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)
+
+#ifndef BOOST_VARIANT_DETAIL_BACKUP_HOLDER_HPP
+#define BOOST_VARIANT_DETAIL_BACKUP_HOLDER_HPP
+
+#include "boost/assert.hpp"
+
+namespace boost {
+namespace detail { namespace variant {
+
+template <typename T>
+class backup_holder
+{
+private: // representation
+
+    T* backup_;
+
+public: // structors
+
+    ~backup_holder()
+    {
+        delete backup_;
+    }
+
+    explicit backup_holder(T* backup)
+        : backup_(backup)
+    {
+    }
+
+    backup_holder(const backup_holder&);
+
+public: // modifiers
+
+    backup_holder& operator=(const backup_holder& rhs)
+    {
+        *backup_ = rhs.get();
+        return *this;
+    }
+
+    backup_holder& operator=(const T& rhs)
+    {
+        *backup_ = rhs;
+        return *this;
+    }
+
+    void swap(backup_holder& rhs)
+    {
+        T* tmp = rhs.backup_;
+        rhs.backup_ = this->backup_;
+        this->backup_ = tmp;
+    }
+
+public: // queries
+
+    T& get()
+    {
+        return *backup_;
+    }
+
+    const T& get() const
+    {
+        return *backup_;
+    }
+
+};
+
+template <typename T>
+backup_holder<T>::backup_holder(const backup_holder&)
+    : backup_(0)
+{
+    // not intended for copy, but do not want to prohibit syntactically
+    BOOST_ASSERT(false);
+}
+
+template <typename T>
+void swap(backup_holder<T>& lhs, backup_holder<T>& rhs)
+{
+    lhs.swap(rhs);
+}
+
+}} // namespace detail::variant
+} // namespace boost
+
+#endif // BOOST_VARIANT_DETAIL_BACKUP_HOLDER_HPP