From 8ce22c666db29726848c522f7d4eac24622ffae4 Mon Sep 17 00:00:00 2001
From: Nicolas Clauvelin <nclauvelin@sendyne.com>
Date: Tue, 13 Mar 2018 17:28:38 -0400
Subject: [PATCH] REVISED OVERFLOW IMPLEMENTATION USING INTEGRAL CONSTANT

The check_overflow implementation now relies on std::integral_constant.
This avoids the definition of a constexpr bool member.
---
 register/Field.h      | 17 +++++++----------
 register/MergeWrite.h |  2 +-
 register/Overflow.h   |  5 +----
 register/Register.h   |  2 +-
 4 files changed, 10 insertions(+), 16 deletions(-)

diff --git a/register/Field.h b/register/Field.h
index a5be8b1..0c283b9 100644
--- a/register/Field.h
+++ b/register/Field.h
@@ -79,14 +79,11 @@ namespace cppreg {
          * This is only used for the template form of the write method.
          */
         template <type value>
-        struct check_overflow {
-            constexpr static const bool result =
-                internals::check_overflow<
-                    parent_register::size,
-                    value,
-                    (mask >> offset)
-                                         >::result::value;
-        };
+        struct check_overflow : internals::check_overflow<
+            parent_register::size,
+            value,
+            (mask >> offset)
+                                                         > {};
 
         //!@ Field read method.
         /**
@@ -147,7 +144,7 @@ namespace cppreg {
         typename std::enable_if<
             !has_shadow
             &&
-            check_overflow<value>::result,
+            check_overflow<value>::value,
             T
                                >::type
         write() noexcept {
@@ -168,7 +165,7 @@ namespace cppreg {
         typename std::enable_if<
             has_shadow
             &&
-            check_overflow<value>::result,
+            check_overflow<value>::value,
             T
                                >::type
         write() noexcept {
diff --git a/register/MergeWrite.h b/register/MergeWrite.h
index 49b0fc2..93963c6 100644
--- a/register/MergeWrite.h
+++ b/register/MergeWrite.h
@@ -131,7 +131,7 @@ namespace cppreg {
         typename std::enable_if<
             (internals::check_overflow<
                 Register::size, new_value, (F::mask >> F::offset)
-                                      >::result::value),
+                                      >::value),
             T
                                >::type&&
         with() const && noexcept {
diff --git a/register/Overflow.h b/register/Overflow.h
index 1f147e6..b5ba809 100644
--- a/register/Overflow.h
+++ b/register/Overflow.h
@@ -34,10 +34,7 @@ namespace internals {
         typename RegisterType<W>::type value,
         typename RegisterType<W>::type limit
     >
-    struct check_overflow {
-        using result =
-        typename std::integral_constant<bool, value <= limit>::type;
-    };
+    struct check_overflow : std::integral_constant<bool, value <= limit> {};
 
 
 }
diff --git a/register/Register.h b/register/Register.h
index 63f0651..b5486fb 100644
--- a/register/Register.h
+++ b/register/Register.h
@@ -110,7 +110,7 @@ namespace cppreg {
         typename std::enable_if<
             internals::check_overflow<
                 size, value, (F::mask >> F::offset)
-                                     >::result::value,
+                                     >::value,
             T
                                >::type&&
         merge_write() noexcept {