Add get_allocator_pointer

include/boost/smart_ptr/allocate_unique.hpp

@@ -1,5 +1,5 @@
 /*
-Copyright 2019 Glen Joseph Fernandes
+Copyright 2019-2021 Glen Joseph Fernandes
 (glenjofe@gmail.com)
 
 Distributed under the Boost Software License, Version 1.0.
@@ -477,6 +477,15 @@ allocate_unique(const A& alloc,
     return c.release();
 }
 
+template<class T, class U, class A>
+inline typename allocator_pointer<typename allocator_rebind<A,
+    typename detail::sp_alloc_value<T>::type>::type>::type
+get_allocator_pointer(const std::unique_ptr<T,
+    alloc_deleter<U, A> >& p) BOOST_NOEXCEPT
+{
+    return p.get().ptr();
+}
+
 } /* boost */
 
 #endif