Ruby FFI notable classes.md

• Library – DSL here
• Object
  • AbstractMemory – Manager for a blob of memory
    • Pointer – C pointer of a blob of memory
      • AutoPointer – with customizable GC
      • Function – C function with fixed args (Library#attach_function)
      • MemoryPointer – with Ruby-managed memory
  • Enum – C Enum (Library#enum)
    • Bitmask – bitmask-style (Library#bitmask)
  • Struct – C Struct
    • ManagedStruct – with customizable GC
    • Union – C Union
  • VariadicInvoker – C function with varargs (Library#attach_function)