Extractor

Extractor

Introduction
Concept Requirements
Notes

Introduction

An Extractor is a class which Boost.Python can use to extract C++ objects from Python objects, and is typically used by facilities that define from_python conversions for "traditional" Python extension types.

Concept Requirements

In the table below, X denotes a model of Extractor and a denotes an instance of a Python object type.

Expression	Type	Semantics
`X::execute(a)`	non-void	Returns the C++ object being extracted. The execute function must not be overloaded.
`&a.ob_type`	`PyTypeObject**`	Points to the `ob_type` field of an object which is layout-compatible with `PyObject`

Notes

Informally, an Extractor's execute member must be a non-overloaded static function whose single argument is a Python object type. Acceptable Python object types include those publicly (and unambiguously) derived from PyObject, and POD types which are layout-compatible with PyObject.