Initial release

engine/vendor/vst3sdk/vstgui4/vstgui/lib/enumbitset.h

@@ -0,0 +1,138 @@
+// This file is part of VSTGUI. It is subject to the license terms
+// in the LICENSE file found in the top-level directory of this
+// distribution and at http://github.com/steinbergmedia/vstgui/LICENSE
+
+#pragma once
+
+#include <initializer_list>
+#include <type_traits>
+
+//------------------------------------------------------------------------
+namespace VSTGUI {
+
+//------------------------------------------------------------------------
+/** enum class bitset
+ *
+ *	example with an integer sequence enumeration:
+ *
+ *		enum class Flag {
+ *			One,
+ *			Two,
+ *			Three
+ *		};
+ *		using Flags = EnumBitset<Flag>;
+ *		Flags f;
+ *		f = Flag::One
+ *		f |= Flag::Two;
+ *		if (f & Flag::One)
+ *		{
+ *		}
+ *
+ *	example with an enumeration where the elements are bitmasks:
+ *
+ *		enum class Flag {
+ *			One = 1 << 0,
+ *			Two = 1 << 1,
+ *			Three = 1 << 2
+ *		};
+ *		using Flags = EnumBitSet<Flag, true>
+ *		Flags f;
+ *		f = Flag::One
+ *		f |= Flag::Two;
+ *		if (f & Flag::One)
+ *		{
+ *		}
+ *
+ */
+template<typename Enum, bool EnumIsBitMask = false>
+struct EnumBitset
+{
+	using value_type = std::underlying_type_t<Enum>;
+
+	constexpr EnumBitset () {}
+	constexpr EnumBitset (Enum initialValue) { exlusive (initialValue); }
+	constexpr EnumBitset (const std::initializer_list<Enum>& list)
+	{
+		for (auto& v : list)
+			add (v);
+	}
+	explicit constexpr EnumBitset (value_type v) : val (v) {}
+
+	constexpr EnumBitset (const EnumBitset&) = default;
+	constexpr EnumBitset& operator= (const EnumBitset&) = default;
+
+	constexpr void exlusive (Enum e) { val = to_value_type (e); }
+	constexpr void add (Enum e) { val |= to_value_type (e); }
+	constexpr void remove (Enum e) { val &= ~to_value_type (e); }
+	constexpr void clear () { val = {}; }
+
+	constexpr bool test (Enum e) const { return (val & to_value_type (e)) != value_type {}; }
+	constexpr bool empty () const { return val == value_type {}; }
+
+	constexpr EnumBitset& operator= (Enum e)
+	{
+		exlusive (e);
+		return *this;
+	}
+	constexpr EnumBitset& operator|= (Enum e)
+	{
+		add (e);
+		return *this;
+	}
+	constexpr EnumBitset& operator^= (Enum e)
+	{
+		remove (e);
+		return *this;
+	}
+	constexpr EnumBitset& operator&= (const EnumBitset& other)
+	{
+		val &= other.val;
+		return *this;
+	}
+	constexpr EnumBitset& operator<< (Enum e)
+	{
+		add (e);
+		return *this;
+	}
+	constexpr EnumBitset& operator<< (const EnumBitset& other)
+	{
+		val |= other.val;
+		return *this;
+	}
+	constexpr EnumBitset& operator>> (Enum e)
+	{
+		remove (e);
+		return *this;
+	}
+	constexpr EnumBitset& operator>> (const EnumBitset& other)
+	{
+		val &= ~other.val;
+		return *this;
+	}
+
+	[[nodiscard]] constexpr EnumBitset operator| (Enum e) const
+	{
+		auto v = *this;
+		v.add (e);
+		return v;
+	}
+	constexpr bool operator& (Enum e) const { return test (e); }
+	constexpr bool operator== (const EnumBitset& other) const { return val == other.val; }
+	constexpr bool operator!= (const EnumBitset& other) const { return val != other.val; }
+
+	constexpr value_type value () const { return val; }
+
+private:
+	constexpr value_type to_value_type (Enum e) const
+	{
+		if constexpr (EnumIsBitMask)
+			return static_cast<value_type> (e);
+		else
+			return 1 << static_cast<value_type> (e);
+	}
+
+	value_type val {};
+};
+
+//------------------------------------------------------------------------
+} // VSTGUI