From 876fec6f5e74dea481c1a97ad7c18d776e4b3501 Mon Sep 17 00:00:00 2001
From: Lynix <lynix680@gmail.com>
Date: Mon, 12 Dec 2016 15:10:37 +0100
Subject: [PATCH] Core/Flags: Make aware of enumeration max value

Preventing it to enable bits that have no corresponding enum value
---
 include/Nazara/Core/Flags.hpp    | 4 ++++
 include/Nazara/Core/Flags.inl    | 9 +++++----
 include/Nazara/Utility/Enums.hpp | 2 ++
 3 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/include/Nazara/Core/Flags.hpp b/include/Nazara/Core/Flags.hpp
index 90e7ed2be..0e4623849 100644
--- a/include/Nazara/Core/Flags.hpp
+++ b/include/Nazara/Core/Flags.hpp
@@ -17,6 +17,7 @@ namespace Nz
 	struct EnumAsFlags
 	{
 		static constexpr bool value = false;
+		static constexpr int  max   = 0;
 	};
 
 	template<typename E>
@@ -47,7 +48,10 @@ namespace Nz
 
 		private:
 			UInt32 m_value;
+			static constexpr UInt32 ValueMask = ((UInt32(1) << (EnumAsFlags<E>::max + 1)) - 1);
 
+		private:
+			BitField m_value;
 	};
 
 	template<typename E> constexpr std::enable_if_t<EnumAsFlags<E>::value, Flags<E>> operator~(E lhs);
diff --git a/include/Nazara/Core/Flags.inl b/include/Nazara/Core/Flags.inl
index 8bf122b69..6e8e25d27 100644
--- a/include/Nazara/Core/Flags.inl
+++ b/include/Nazara/Core/Flags.inl
@@ -21,7 +21,7 @@ namespace Nz
 	* Uses a bitfield to builds the flag value. (e.g. if bit 0 is active, then Enum value 0 will be set as active).
     */
 	template<typename E>
-	constexpr Flags<E>::Flags(UInt32 value) :
+	constexpr Flags<E>::Flags(BitField value) :
 	m_value(value)
 	{
 	}
@@ -58,7 +58,7 @@ namespace Nz
 	* This will convert to a bitfield value.
 	*/
 	template<typename E>
-	constexpr Flags<E>::operator UInt32() const
+	constexpr Flags<E>::operator BitField() const
 	{
 		return m_value;
 	}
@@ -72,7 +72,7 @@ namespace Nz
 	template<typename E>
 	constexpr Flags<E> Flags<E>::operator~() const
 	{
-		return Flags(~m_value);
+		return Flags((~m_value) & ValueMask);
 	}
 
 	/*!
@@ -115,7 +115,7 @@ namespace Nz
 	template<typename E>
 	constexpr Flags<E> Flags<E>::operator^(Flags rhs) const
 	{
-		return Flags(m_value ^ rhs.m_value);
+		return Flags((m_value ^ rhs.m_value) & ValueMask);
 	}
 
 	/*!
@@ -191,6 +191,7 @@ namespace Nz
 	/*constexpr*/ Flags<E>& Flags<E>::operator^=(Flags rhs)
 	{
 		m_value ^= rhs.m_value;
+		m_value &= ValueMask;
 
 		return *this;
 	}
diff --git a/include/Nazara/Utility/Enums.hpp b/include/Nazara/Utility/Enums.hpp
index 69df340bd..fd9001d44 100644
--- a/include/Nazara/Utility/Enums.hpp
+++ b/include/Nazara/Utility/Enums.hpp
@@ -65,6 +65,7 @@ namespace Nz
 	struct EnumAsFlags<BufferUsage>
 	{
 		static constexpr bool value = true;
+		static constexpr int  max   = BufferUsage_Max;
 	};
 
 	using BufferUsageFlags = Flags<BufferUsage>;
@@ -456,6 +457,7 @@ namespace Nz
 	struct EnumAsFlags<WindowStyle>
 	{
 		static constexpr bool value = true;
+		static constexpr int  max   = WindowStyle_Max;
 	};
 
 	using WindowStyleFlags = Flags<WindowStyle>;