# Object Implementation Support

This chapter describes the functions, types, and macros used when defining new object types.

- Allocating Objects on the Heap
- Common Object Structures
  - Base object types and macros
  - Implementing functions and methods
  - Accessing attributes of extension types
- Type Objects
  - Quick Reference
    - “tp slots”
    - sub-slots
    - slot typedefs
  - PyTypeObject Definition
  - PyObject Slots
  - PyVarObject Slots
  - PyTypeObject Slots
  - Heap Types
- Number Object Structures
- Mapping Object Structures
- Sequence Object Structures
- Buffer Object Structures
- Async Object Structures
- Slot Type typedefs
- Examples
- Supporting Cyclic Garbage Collection