1 files changed, 30 insertions, 17 deletions

diff --git a/include/cru/base/Bitmask.h b/include/cru/base/Bitmask.h
index 7606f784..ba5b37f2 100644
--- a/include/cru/base/Bitmask.h
+++ b/include/cru/base/Bitmask.h
@@ -8,50 +8,63 @@ struct Bitmask final {
   using Underlying = TUnderlying;
 
   constexpr Bitmask() : value(0) {}
-  constexpr explicit Bitmask(TUnderlying value) : value(value) {}
+  constexpr explicit Bitmask(Underlying value) : value(value) {}
 
   // Start from 1.
   static constexpr Bitmask FromOffset(int offset) {
     if (offset == 0) return {};
-    return Bitmask(static_cast<TUnderlying>(1u << (offset - 1)));
+    return Bitmask(static_cast<Underlying>(Underlying(1) << (offset - 1)));
   }
 
   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) {
+  constexpr Bitmask operator|(Bitmask rhs) const {
+    return Bitmask(value | rhs.value);
+  }
+  constexpr Bitmask operator&(Bitmask rhs) const {
+    return Bitmask(value & rhs.value);
+  }
+  constexpr Bitmask operator^(Bitmask rhs) const {
+    return Bitmask(value ^ rhs.value);
+  }
+  constexpr Bitmask operator~() const { return Bitmask(~value); }
+  constexpr Bitmask& operator|=(Bitmask rhs) {
     value |= rhs.value;
     return *this;
   }
-  Bitmask& operator&=(Bitmask rhs) {
+  constexpr Bitmask& operator&=(Bitmask rhs) {
     value &= rhs.value;
     return *this;
   }
-  Bitmask& operator^=(Bitmask rhs) {
+  constexpr 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; }
+  constexpr bool operator==(Bitmask rhs) const {
+    return this->value == rhs.value;
+  }
 
-  explicit operator TUnderlying() const { return value; }
-  operator bool() const { return value != 0; }
+  constexpr explicit operator Underlying() const { return value; }
+  constexpr explicit operator bool() const { return value != 0; }
 
-  TUnderlying value;
+  Underlying 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 {
+  constexpr std::size_t operator()(
+      cru::Bitmask<Tag, TUnderlying> bitmask) const {
     return std::hash<TUnderlying>{}(bitmask.value);
   }
 };
 }  // namespace std
+
+#define CRU_DEFINE_BITMASK(name)                   \
+  namespace details {                              \
+  struct name##Tag {};                             \
+  }                                                \
+  using name = ::cru::Bitmask<details::name##Tag>; \
+  struct name##s