1 files changed, 55 insertions, 0 deletions
diff --git a/include/cru/base/Bitmask.h b/include/cru/base/Bitmask.h
new file mode 100644
index 00000000..9b6b8957
--- /dev/null
+++ b/include/cru/base/Bitmask.h
@@ -0,0 +1,55 @@
+#pragma once
+
+#include <functional>
+
+namespace cru {
+template <typename Tag, typename TUnderlying = unsigned>
+struct Bitmask final {
+  using Underlying = TUnderlying;
+
+  constexpr Bitmask() : value(0) {}
+  constexpr explicit Bitmask(TUnderlying value) : value(value) {}
+
+  static constexpr Bitmask FromOffset(int offset) {
+    return Bitmask(static_cast<TUnderlying>(1u << offset));
+  }
+
+  constexpr bool Has(Bitmask rhs) const { return (value & rhs.value) != 0; }
+
+  Bitmask operator|(Bitmask rhs) const { return Bitmask(value | rhs.value); }
+  Bitmask operator&(Bitmask rhs) const { return Bitmask(value & rhs.value); }
+  Bitmask operator^(Bitmask rhs) const { return Bitmask(value ^ rhs.value); }
+  Bitmask operator~() const { return Bitmask(~value); }
+  Bitmask& operator|=(Bitmask rhs) {
+    value |= rhs.value;
+    return *this;
+  }
+  Bitmask& operator&=(Bitmask rhs) {
+    value &= rhs.value;
+    return *this;
+  }
+  Bitmask& operator^=(Bitmask rhs) {
+    value ^= rhs.value;
+    return *this;
+  }
+
+  bool operator==(Bitmask rhs) const { return this->value == rhs.value; }
+  bool operator!=(Bitmask rhs) const { return this->value != rhs.value; }
+
+  explicit operator TUnderlying() const { return value; }
+  operator bool() const { return value != 0; }
+
+  TUnderlying value;
+};
+}  // namespace cru
+
+namespace std {
+template <typename Tag, typename TUnderlying>
+struct hash<cru::Bitmask<Tag, TUnderlying>> {
+  using Bitmask = cru::Bitmask<Tag, TUnderlying>;
+
+  std::size_t operator()(Bitmask bitmask) const {
+    return std::hash<TUnderlying>{}(bitmask.value);
+  }
+};
+}  // namespace std