Introduce o3tl::underlyingEnumValue

Change-Id: I6554eb86326159b0da707539f45c411f61c0f3de
Reviewed-on: https://gerrit.libreoffice.org/68761
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

2 files changed, 77 insertions, 60 deletions

diff --git a/include/o3tl/typed_flags_set.hxx b/include/o3tl/typed_flags_set.hxx
index 188258febc58..bf795908bad5 100644
--- a/include/o3tl/typed_flags_set.hxx
+++ b/include/o3tl/typed_flags_set.hxx
@@ -25,6 +25,7 @@
 #include <cassert>
 #include <type_traits>
 
+#include <o3tl/underlyingenumvalue.hxx>
 #include <sal/types.h>
 
 namespace o3tl {
@@ -104,10 +105,10 @@ template<typename E>
 constexpr typename o3tl::typed_flags<E>::Wrap operator ~(E rhs) {
     assert(
         o3tl::detail::isNonNegative(
-            static_cast<typename std::underlying_type<E>::type>(rhs)));
+            o3tl::underlyingEnumValue(rhs)));
     return static_cast<typename o3tl::typed_flags<E>::Wrap>(
         o3tl::typed_flags<E>::mask
-        & ~static_cast<typename std::underlying_type<E>::type>(rhs));
+        & ~o3tl::underlyingEnumValue(rhs));
 }
 
 template<typename E> constexpr typename o3tl::typed_flags<E>::Wrap operator ~(
@@ -115,7 +116,7 @@ template<typename E> constexpr typename o3tl::typed_flags<E>::Wrap operator ~(
 {
     return static_cast<typename o3tl::typed_flags<E>::Wrap>(
         o3tl::typed_flags<E>::mask
-        & ~static_cast<typename std::underlying_type<E>::type>(rhs));
+        & ~o3tl::underlyingEnumValue<E>(rhs));
 }
 
 template<typename E> constexpr typename o3tl::typed_flags<E>::Wrap operator ^(
@@ -123,13 +124,13 @@ template<typename E> constexpr typename o3tl::typed_flags<E>::Wrap operator ^(
 {
     assert(
         o3tl::detail::isNonNegative(
-            static_cast<typename std::underlying_type<E>::type>(lhs)));
+            o3tl::underlyingEnumValue(lhs)));
     assert(
         o3tl::detail::isNonNegative(
-            static_cast<typename std::underlying_type<E>::type>(rhs)));
+            o3tl::underlyingEnumValue(rhs)));
     return static_cast<typename o3tl::typed_flags<E>::Wrap>(
-        static_cast<typename std::underlying_type<E>::type>(lhs)
-        ^ static_cast<typename std::underlying_type<E>::type>(rhs));
+        o3tl::underlyingEnumValue(lhs)
+        ^ o3tl::underlyingEnumValue(rhs));
 }
 
 template<typename E> constexpr typename o3tl::typed_flags<E>::Wrap operator ^(
@@ -137,10 +138,10 @@ template<typename E> constexpr typename o3tl::typed_flags<E>::Wrap operator ^(
 {
     assert(
         o3tl::detail::isNonNegative(
-            static_cast<typename std::underlying_type<E>::type>(lhs)));
+            o3tl::underlyingEnumValue(lhs)));
     return static_cast<typename o3tl::typed_flags<E>::Wrap>(
-        static_cast<typename std::underlying_type<E>::type>(lhs)
-        ^ static_cast<typename std::underlying_type<E>::type>(rhs));
+        o3tl::underlyingEnumValue(lhs)
+        ^ o3tl::underlyingEnumValue<E>(rhs));
 }
 
 template<typename E> constexpr typename o3tl::typed_flags<E>::Wrap operator ^(
@@ -148,10 +149,10 @@ template<typename E> constexpr typename o3tl::typed_flags<E>::Wrap operator ^(
 {
     assert(
         o3tl::detail::isNonNegative(
-            static_cast<typename std::underlying_type<E>::type>(rhs)));
+            o3tl::underlyingEnumValue(rhs)));
     return static_cast<typename o3tl::typed_flags<E>::Wrap>(
-        static_cast<typename std::underlying_type<E>::type>(lhs)
-        ^ static_cast<typename std::underlying_type<E>::type>(rhs));
+        o3tl::underlyingEnumValue<E>(lhs)
+        ^ o3tl::underlyingEnumValue(rhs));
 }
 
 template<typename W> constexpr
@@ -159,25 +160,21 @@ typename o3tl::typed_flags<typename W::Unwrapped::Self>::Wrap operator ^(
     W lhs, W rhs)
 {
     return static_cast<W>(
-        static_cast<
-            typename std::underlying_type<typename W::Unwrapped::Self>::type>(
-                lhs)
-        ^ static_cast<
-            typename std::underlying_type<typename W::Unwrapped::Self>::type>(
-                rhs));
+        o3tl::underlyingEnumValue<typename W::Unwrapped::Self>(lhs)
+        ^ o3tl::underlyingEnumValue<typename W::Unwrapped::Self>(rhs));
 }
 
 template<typename E>
 constexpr typename o3tl::typed_flags<E>::Wrap operator &(E lhs, E rhs) {
     assert(
         o3tl::detail::isNonNegative(
-            static_cast<typename std::underlying_type<E>::type>(lhs)));
+            o3tl::underlyingEnumValue(lhs)));
     assert(
         o3tl::detail::isNonNegative(
-            static_cast<typename std::underlying_type<E>::type>(rhs)));
+            o3tl::underlyingEnumValue(rhs)));
     return static_cast<typename o3tl::typed_flags<E>::Wrap>(
-        static_cast<typename std::underlying_type<E>::type>(lhs)
-        & static_cast<typename std::underlying_type<E>::type>(rhs));
+        o3tl::underlyingEnumValue(lhs)
+        & o3tl::underlyingEnumValue(rhs));
 }
 
 template<typename E> constexpr typename o3tl::typed_flags<E>::Wrap operator &(
@@ -185,10 +182,10 @@ template<typename E> constexpr typename o3tl::typed_flags<E>::Wrap operator &(
 {
     assert(
         o3tl::detail::isNonNegative(
-            static_cast<typename std::underlying_type<E>::type>(lhs)));
+            o3tl::underlyingEnumValue(lhs)));
     return static_cast<typename o3tl::typed_flags<E>::Wrap>(
-        static_cast<typename std::underlying_type<E>::type>(lhs)
-        & static_cast<typename std::underlying_type<E>::type>(rhs));
+        o3tl::underlyingEnumValue(lhs)
+        & o3tl::underlyingEnumValue<E>(rhs));
 }
 
 template<typename E> constexpr typename o3tl::typed_flags<E>::Wrap operator &(
@@ -196,10 +193,10 @@ template<typename E> constexpr typename o3tl::typed_flags<E>::Wrap operator &(
 {
     assert(
         o3tl::detail::isNonNegative(
-            static_cast<typename std::underlying_type<E>::type>(rhs)));
+            o3tl::underlyingEnumValue(rhs)));
     return static_cast<typename o3tl::typed_flags<E>::Wrap>(
-        static_cast<typename std::underlying_type<E>::type>(lhs)
-        & static_cast<typename std::underlying_type<E>::type>(rhs));
+        o3tl::underlyingEnumValue<E>(lhs)
+        & o3tl::underlyingEnumValue(rhs));
 }
 
 template<typename W> constexpr
@@ -207,25 +204,21 @@ typename o3tl::typed_flags<typename W::Unwrapped::Self>::Wrap operator &(
     W lhs, W rhs)
 {
     return static_cast<W>(
-        static_cast<
-            typename std::underlying_type<typename W::Unwrapped::Self>::type>(
-                lhs)
-        & static_cast<
-            typename std::underlying_type<typename W::Unwrapped::Self>::type>(
-                rhs));
+        o3tl::underlyingEnumValue<typename W::Unwrapped::Self>(lhs)
+        & o3tl::underlyingEnumValue<typename W::Unwrapped::Self>(rhs));
 }
 
 template<typename E>
 constexpr typename o3tl::typed_flags<E>::Wrap operator |(E lhs, E rhs) {
     assert(
         o3tl::detail::isNonNegative(
-            static_cast<typename std::underlying_type<E>::type>(lhs)));
+            o3tl::underlyingEnumValue(lhs)));
     assert(
         o3tl::detail::isNonNegative(
-            static_cast<typename std::underlying_type<E>::type>(rhs)));
+            o3tl::underlyingEnumValue(rhs)));
     return static_cast<typename o3tl::typed_flags<E>::Wrap>(
-        static_cast<typename std::underlying_type<E>::type>(lhs)
-        | static_cast<typename std::underlying_type<E>::type>(rhs));
+        o3tl::underlyingEnumValue(lhs)
+        | o3tl::underlyingEnumValue(rhs));
 }
 
 template<typename E> constexpr typename o3tl::typed_flags<E>::Wrap operator |(
@@ -233,10 +226,10 @@ template<typename E> constexpr typename o3tl::typed_flags<E>::Wrap operator |(
 {
     assert(
         o3tl::detail::isNonNegative(
-            static_cast<typename std::underlying_type<E>::type>(lhs)));
+            o3tl::underlyingEnumValue(lhs)));
     return static_cast<typename o3tl::typed_flags<E>::Wrap>(
-        static_cast<typename std::underlying_type<E>::type>(lhs)
-        | static_cast<typename std::underlying_type<E>::type>(rhs));
+        o3tl::underlyingEnumValue(lhs)
+        | o3tl::underlyingEnumValue<E>(rhs));
 }
 
 template<typename E> constexpr typename o3tl::typed_flags<E>::Wrap operator |(
@@ -244,10 +237,10 @@ template<typename E> constexpr typename o3tl::typed_flags<E>::Wrap operator |(
 {
     assert(
         o3tl::detail::isNonNegative(
-            static_cast<typename std::underlying_type<E>::type>(rhs)));
+            o3tl::underlyingEnumValue(rhs)));
     return static_cast<typename o3tl::typed_flags<E>::Wrap>(
-        static_cast<typename std::underlying_type<E>::type>(lhs)
-        | static_cast<typename std::underlying_type<E>::type>(rhs));
+        o3tl::underlyingEnumValue<E>(lhs)
+        | o3tl::underlyingEnumValue(rhs));
 }
 
 template<typename W> constexpr
@@ -255,22 +248,18 @@ typename o3tl::typed_flags<typename W::Unwrapped::Self>::Wrap operator |(
     W lhs, W rhs)
 {
     return static_cast<W>(
-        static_cast<
-            typename std::underlying_type<typename W::Unwrapped::Self>::type>(
-                lhs)
-        | static_cast<
-            typename std::underlying_type<typename W::Unwrapped::Self>::type>(
-                rhs));
+        o3tl::underlyingEnumValue<typename W::Unwrapped::Self>(lhs)
+        | o3tl::underlyingEnumValue<typename W::Unwrapped::Self>(rhs));
 }
 
 template<typename E>
 inline typename o3tl::typed_flags<E>::Self operator &=(E & lhs, E rhs) {
     assert(
         o3tl::detail::isNonNegative(
-            static_cast<typename std::underlying_type<E>::type>(lhs)));
+            o3tl::underlyingEnumValue(lhs)));
     assert(
         o3tl::detail::isNonNegative(
-            static_cast<typename std::underlying_type<E>::type>(rhs)));
+            o3tl::underlyingEnumValue(rhs)));
     lhs = lhs & rhs;
     return lhs;
 }
@@ -281,7 +270,7 @@ inline typename o3tl::typed_flags<E>::Self operator &=(
 {
     assert(
         o3tl::detail::isNonNegative(
-            static_cast<typename std::underlying_type<E>::type>(lhs)));
+            o3tl::underlyingEnumValue(lhs)));
     lhs = lhs & rhs;
     return lhs;
 }
@@ -290,10 +279,10 @@ template<typename E>
 inline typename o3tl::typed_flags<E>::Self operator |=(E & lhs, E rhs) {
     assert(
         o3tl::detail::isNonNegative(
-            static_cast<typename std::underlying_type<E>::type>(lhs)));
+            o3tl::underlyingEnumValue(lhs)));
     assert(
         o3tl::detail::isNonNegative(
-            static_cast<typename std::underlying_type<E>::type>(rhs)));
+            o3tl::underlyingEnumValue(rhs)));
     lhs = lhs | rhs;
     return lhs;
 }
@@ -304,7 +293,7 @@ inline typename o3tl::typed_flags<E>::Self operator |=(
 {
     assert(
         o3tl::detail::isNonNegative(
-            static_cast<typename std::underlying_type<E>::type>(lhs)));
+            o3tl::underlyingEnumValue(lhs)));
     lhs = lhs | rhs;
     return lhs;
 }
@@ -313,10 +302,10 @@ template<typename E>
 inline typename o3tl::typed_flags<E>::Self operator ^=(E & lhs, E rhs) {
     assert(
         o3tl::detail::isNonNegative(
-            static_cast<typename std::underlying_type<E>::type>(lhs)));
+            o3tl::underlyingEnumValue(lhs)));
     assert(
         o3tl::detail::isNonNegative(
-            static_cast<typename std::underlying_type<E>::type>(rhs)));
+            o3tl::underlyingEnumValue(rhs)));
     lhs = lhs ^ rhs;
     return lhs;
 }
@@ -327,7 +316,7 @@ inline typename o3tl::typed_flags<E>::Self operator ^=(
 {
     assert(
         o3tl::detail::isNonNegative(
-            static_cast<typename std::underlying_type<E>::type>(lhs)));
+            o3tl::underlyingEnumValue(lhs)));
     lhs = lhs ^ rhs;
     return lhs;
 }
diff --git a/include/o3tl/underlyingenumvalue.hxx b/include/o3tl/underlyingenumvalue.hxx
new file mode 100644
index 000000000000..1684b2da17d9
--- /dev/null
+++ b/include/o3tl/underlyingenumvalue.hxx
@@ -0,0 +1,28 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#ifndef INCLUDED_O3TL_UNDERLYINGENUMVALUE_HXX
+#define INCLUDED_O3TL_UNDERLYINGENUMVALUE_HXX
+
+#include <sal/config.h>
+
+#include <type_traits>
+
+namespace o3tl
+{
+// For a value e of an enumeration type T, return the corresponding value of T's underlying type:
+template <typename T> constexpr std::underlying_type_t<T> underlyingEnumValue(T e)
+{
+    return static_cast<std::underlying_type_t<T>>(e);
+}
+}
+
+#endif
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */