Stretchy bitflags - Nifty code snippet from Ryan Fleury shared on Handmade Network discord

EntityProperties.cpp

enum EntityProperty
{
  EntityProperty_IsActive,
  EntityProperty_RenderModel,
  EntityProperty_Hostile,
  EntityProperty_OnFire,
  EntityProperty_SomethingElse,
  EntityProperty_Count
};

// In Entity:
u64 properties[(EntityProperty_Count+63)/64];

b32 EntityHasProperty(Entity *entity, EntityProperty property)
{
  return !!(entity->properties[property/64] & (1ull << (property%64)));
}

void SetEntityProperty(Entity *entity, EntityProperty property)
{
  entity->properties[property/64] |= (1ull << (property%64));
}