From 30d57aec7d42b3657a4775ecede1c14d3ddde1bb Mon Sep 17 00:00:00 2001
From: q66 <daniel@octaforge.org>
Date: Thu, 9 Jul 2015 20:23:35 +0100
Subject: [PATCH] add And, Or and Not type traits (for AND/ORing together
 integral constants in a SFINAE aware way)

---
 octa/type_traits.hh | 45 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/octa/type_traits.hh b/octa/type_traits.hh
index 0438b9e..4466ba8 100644
--- a/octa/type_traits.hh
+++ b/octa/type_traits.hh
@@ -67,6 +67,50 @@ using False = IntegralConstant<bool, false>;
 
 template<typename T, T val> constexpr T IntegralConstant<T, val>::value;
 
+/* and */
+
+namespace detail {
+    template<bool B, typename ...A> struct AndBase;
+
+    template<typename ...A>
+    struct AndBase<false, A...>: False {};
+
+    template<>
+    struct AndBase<true>: True {};
+
+    template<typename T>
+    struct AndBase<true, T>: IntegralConstant<bool, T::Type::value> {};
+
+    template<typename T, typename ...A>
+    struct AndBase<true, T, A...>: AndBase<T::Type::value, A...> {};
+}
+
+template<typename T, typename ...A>
+struct And: detail::AndBase<T::Type::value, A...> {};
+
+/* or */
+
+namespace detail {
+    template<bool B, typename ...A> struct OrBase;
+
+    template<>
+    struct OrBase<false>: False {};
+
+    template<typename T, typename ...A>
+    struct OrBase<false, T, A...>: OrBase<T::Type::value, A...> {};
+
+    template<typename ...A>
+    struct OrBase<true, A...>: True {};
+}
+
+template<typename T, typename ...A>
+struct Or: detail::OrBase<T::Type::value, A...> {};
+
+/* not */
+
+template<typename T>
+struct Not: IntegralConstant<bool, !T::Type::value> {};
+
 /* is void */
 
 namespace detail {
@@ -1193,6 +1237,7 @@ namespace detail {
 
 template<typename T>
 using UnderlyingType = typename detail::UnderlyingTypeBase<T>::Type;
+
 } /* namespace octa */
 
 #endif
\ No newline at end of file