Add free function to_address

include/boost/core/pointer_traits.hpp

@@ -239,6 +239,20 @@ struct pointer_traits<T*> {
 };
 #endif
 
+template<class T>
+inline typename pointer_traits<T>::element_type*
+to_address(const T& v) BOOST_NOEXCEPT
+{
+    return pointer_traits<T>::to_address(v);
+}
+
+template<class T>
+inline T*
+to_address(T* v) BOOST_NOEXCEPT
+{
+    return v;
+}
+
 } /* boost */
 
 #endif

test/Jamfile.v2

@@ -116,6 +116,7 @@ run pointer_traits_element_type_test.cpp ;
 run pointer_traits_difference_type_test.cpp ;
 run pointer_traits_rebind_test.cpp ;
 run pointer_traits_pointer_to_test.cpp ;
+run to_address_test.cpp ;
 
 use-project /boost/core/swap : ./swap ;
 build-project ./swap ;

test/to_address_test.cpp

@@ -0,0 +1,63 @@
+/*
+Copyright 2017 Glen Joseph Fernandes
+(glenjofe@gmail.com)
+
+Distributed under the Boost Software License, Version 1.0.
+(http://www.boost.org/LICENSE_1_0.txt)
+*/
+#include <boost/core/pointer_traits.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+template<class T>
+class pointer {
+public:
+    typedef typename boost::pointer_traits<T>::element_type element_type;
+    pointer(T value)
+        : value_(value) { }
+    T operator->() const BOOST_NOEXCEPT {
+        return value_;
+    }
+private:
+    T value_;
+};
+
+int main()
+{
+    int i = 0;
+    {
+        typedef int* type;
+        type p = &i;
+        BOOST_TEST(boost::to_address(p) == &i);
+    }
+    {
+        typedef pointer<int*> type;
+        type p(&i);
+        BOOST_TEST(boost::to_address(p) == &i);
+    }
+    {
+        typedef pointer<pointer<int*> > type;
+        type p(&i);
+        BOOST_TEST(boost::to_address(p) == &i);
+    }
+    {
+        typedef void* type;
+        type p = &i;
+        BOOST_TEST(boost::to_address(p) == &i);
+    }
+    {
+        typedef pointer<void*> type;
+        type p(&i);
+        BOOST_TEST(boost::to_address(p) == &i);
+    }
+    {
+        typedef const int* type;
+        type p = &i;
+        BOOST_TEST(boost::to_address(p) == &i);
+    }
+    {
+        typedef pointer<const int*> type;
+        type p(&i);
+        BOOST_TEST(boost::to_address(p) == &i);
+    }
+    return boost::report_errors();
+}