Replace Boost.MPL with Boost.MP11 in promote_integral.hpp

include/boost/gil/promote_integral.hpp

@@ -2,6 +2,8 @@
 //
 // Copyright (c) 2015, Oracle and/or its affiliates.
 // Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle
+// 
+// Copyright (c) 2020, Debabrata Mandal <mandaldebabrata123@gmail.com>
 //
 // Licensed under the Boost Software License version 1.0.
 // http://www.boost.org/users/license.html
@@ -12,15 +14,12 @@
 //  - Rename include guards
 //  - Remove support for boost::multiprecision types
 //  - Remove support for 128-bit integer types
+//  - Replace mpl meta functions with mp11 equivalents
 //
 #ifndef BOOST_GIL_PROMOTE_INTEGRAL_HPP
 #define BOOST_GIL_PROMOTE_INTEGRAL_HPP
 
-#include <boost/mpl/begin.hpp>
-#include <boost/mpl/deref.hpp>
-#include <boost/mpl/end.hpp>
-#include <boost/mpl/list.hpp>
-#include <boost/mpl/next.hpp>
+#include <boost/mp11/list.hpp>
 
 #include <climits>
 #include <cstddef>
@@ -47,13 +46,13 @@ struct bit_size<T, true> : std::integral_constant<std::size_t, (CHAR_BIT * sizeo
 template
 <
     typename T,
-    typename Iterator,
-    typename EndIterator,
+    typename type_list,
     std::size_t MinSize
 >
 struct promote_to_larger
 {
-    using current_type = typename boost::mpl::deref<Iterator>::type;
+    using current_type = boost::mp11::mp_first<type_list>;
+    using list_after_front = boost::mp11::mp_rest<type_list>;
 
     using type = typename std::conditional
         <
@@ -62,17 +61,16 @@ struct promote_to_larger
             typename promote_to_larger
                 <
                     T,
-                    typename boost::mpl::next<Iterator>::type,
-                    EndIterator,
+                    list_after_front,
                     MinSize
                 >::type
         >::type;
 };
 
 // The following specialization is required to finish the loop over
 // all list elements
-template <typename T, typename EndIterator, std::size_t MinSize>
-struct promote_to_larger<T, EndIterator, EndIterator, MinSize>
+template <typename T, std::size_t MinSize>
+struct promote_to_larger<T, boost::mp11::mp_list<>, MinSize>
 {
     // if promotion fails, keep the number T
     // (and cross fingers that overflow will not occur)
@@ -148,7 +146,7 @@ class promote_integral
 
     // Define the list of signed integral types we are going to use
     // for promotion
-    using signed_integral_types = boost::mpl::list
+    using signed_integral_types = boost::mp11::mp_list
         <
             short, int, long
 #if defined(BOOST_HAS_LONG_LONG)
@@ -158,7 +156,7 @@ class promote_integral
 
     // Define the list of unsigned integral types we are going to use
     // for promotion
-    using unsigned_integral_types = boost::mpl::list
+    using unsigned_integral_types = boost::mp11::mp_list
         <
             unsigned short, unsigned int, unsigned long, std::size_t
 #if defined(BOOST_HAS_LONG_LONG)
@@ -180,8 +178,7 @@ class promote_integral
     using type = typename detail::promote_integral::promote_to_larger
         <
             T,
-            typename boost::mpl::begin<integral_types>::type,
-            typename boost::mpl::end<integral_types>::type,
+            integral_types,
             min_bit_size_type::value
         >::type;
 };