Added boost header

test/external/boost/parameter/aux_/maybe.hpp

@@ -0,0 +1,120 @@
+// Copyright Daniel Wallin 2006. Use, modification and distribution is
+// subject to 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)
+
+//
+// 2009.10.21 TDS remove depenency on boost::python::detail::referent_storage
+//
+#ifndef BOOST_PARAMETER_MAYBE_091021_HPP
+# define BOOST_PARAMETER_MAYBE_091021_HPP
+
+# include <boost/mpl/if.hpp>
+# include <boost/mpl/identity.hpp>
+# include <boost/type_traits/is_reference.hpp>
+# include <boost/type_traits/add_reference.hpp>
+# include <boost/optional.hpp>
+# include <boost/aligned_storage.hpp>
+# include <boost/type_traits/remove_cv.hpp>
+# include <boost/type_traits/add_const.hpp>
+# include <boost/parameter/aux_/is_maybe.hpp>
+
+namespace boost { namespace parameter { namespace aux {
+
+template <class T> struct referent_size;
+
+template <class T>
+struct referent_size<T&>
+{
+  BOOST_STATIC_CONSTANT(std::size_t, value = sizeof(T));
+};
+
+// A metafunction returning a POD type which can store U, where T ==
+// U&. If T is not a reference type, returns a POD which can store T.
+template <class T>
+struct referent_storage
+{
+  typedef typename boost::aligned_storage<
+    referent_size<T>::value
+    >::type type;
+};
+
+template <class T>
+struct maybe : maybe_base
+{
+    typedef typename add_reference<
+# if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))
+        T const
+# else
+        typename add_const<T>::type
+# endif
+    >::type reference;
+
+    typedef typename remove_cv<
+        BOOST_DEDUCED_TYPENAME remove_reference<reference>::type
+    >::type non_cv_value;
+
+    explicit maybe(T value_)
+      : value(value_)
+      , constructed(false)
+    {}
+
+    maybe()
+      : constructed(false)
+    {}
+
+    ~maybe()
+    {
+        if (constructed)
+            this->destroy();
+    }
+
+    reference construct(reference value_) const
+    {
+        return value_;
+    }
+
+    template <class U>
+    reference construct2(U const& value_) const
+    {
+        new (m_storage.address()) non_cv_value(value_);
+        constructed = true;
+        return *(non_cv_value*)m_storage.address();
+    }
+
+    template <class U>
+    reference construct(U const& value_) const
+    {
+        return this->construct2(value_);
+    }
+
+    void destroy()
+    {
+        ((non_cv_value*)m_storage.address())->~non_cv_value();
+    }
+
+    typedef reference(maybe<T>::*safe_bool)() const;
+
+    operator safe_bool() const
+    {
+        return value ? &maybe<T>::get : 0 ;
+    }
+
+    reference get() const
+    {
+        return value.get();
+    }
+
+private:
+    boost::optional<T> value;
+    mutable bool constructed;
+
+
+    mutable typename referent_storage<
+        reference
+    >::type m_storage;
+};
+
+}}} // namespace boost::parameter::aux
+
+#endif // BOOST_PARAMETER_MAYBE_060211_HPP
+