lass::python Namespace Reference

Detailed Description

Comprehensive C++ to Python binding library.

The lass::python namespace provides a comprehensive Python binding system that allows easy integration between C++ code and Python scripts. Lass Python bindings support both native Python-aware classes and shadow classes for existing C++ types.

Key Components:

• ModuleDefinition: Macros to create and configure Python modules
• ClassDefinition: Macros to export C++ classes as Python types
• PyObjectPlus: Base class for Python-aware C++ objects
• Shadow Classes: Wrapper system for existing non-Python-aware C++ classes
• PyExportTraits: Type conversion system between C++ and Python objects
• Overload Resolution: Automatic dispatcher generation for overloaded functions/methods

Class Export Approaches:

1. Native Python Classes: C++ classes that inherit from PyObjectPlus and are designed to be Python-compatible from the start
2. Shadow Classes: Wrapper classes for existing C++ types using PY_SHADOW_CLASS macros - the shadow inherits from PyObjectPlus and wraps the original type

Binding Features:

• Multiple constructor overloads with automatic dispatching
• Method overloading mixing member functions and free functions
• Property binding with getter/setter pairs or direct member access
• Python special methods (__add__, __str__, __eq__, etc.)
• Static methods and class constants
• Nested classes and enumerations
• Automatic type conversion and argument validation
• Exception mapping between C++ and Python

Namespaces
namespace	methods
	Predefined constants for Python special methods (magic methods) that can be used as method names in class export macros.

Data Structures
struct	ArgumentTraits
	by copy. More...
struct	ArgumentTraits< const char * >
	by SharedPtr More...
struct	ArgumentTraits< const T & >
	by reference to const object. More...
struct	ArgumentTraits< const T * >
	by non-const pointer to const object. More...
struct	ArgumentTraits< const T >
	by const copy. More...
struct	ArgumentTraits< T & >
	by reference to non-const object. More...
struct	ArgumentTraits< T * >
	by non-const pointer to non-const object. More...
struct	ArgumentTraits< util::SharedPtr< T, S, C > >
	by SharedPtr More...
class	ContainerRangeView
	View that adapts a C++ Range (begin()/end()) to a PyIteratorRange. More...
class	EnumDefinition
	Definition of a general enum.Enum-derived enum type in Python. More...
class	EnumDefinitionBase
	Base class of all enum definitions. More...
class	FreeIndexedRangeView
	View that adapts index-based element access to a PyIteratorRange. More...
class	FreeRangeView
	View that adapts free iterator accessors to a PyIteratorRange. More...
class	IndexedRangeView
	View that adapts index-based element access to a PyIteratorRange. More...
class	IntEnumDefinition
	Definition of an enum.IntEnum-derived enum type in Python. More...
class	IntFlagDefinition
	Definition of an enum.IntFlag-derived enum type in Python. More...
struct	IsPyObject
	meta function to detect if a type is a PyObject-derived type More...
class	LockGIL
	acquire the GIL for the current scope. More...
class	MaybeNone
	Wrapper to type-hint return values in Python that maybe None but not likely. More...
class	MemberRangeView
	View that adapts member iterator accessors to a PyIteratorRange. More...
class	ModuleDefinition
	Definition of a Python module. More...
class	MultiCallback
	MultiCallback. More...
class	NoNone
	Wrapper to prevent None values being passed to and from Python. More...
struct	PyExportTraits
	by copy, general case assumes shadow type or PyObjectPlus based type. More...
struct	PyExportTraits< const char16_t * >
	UTF-16 const char16_t* string is mapped to Python str | None, as it can be null. More...
struct	PyExportTraits< const char32_t * >
	UTF-32 const char32_t* string is mapped to Python str | None, as it can be null. More...
struct	PyExportTraits< const T >
	constant objects can only be build. More...
struct	PyExportTraits< ContainerRangeView< SelfType, ValueType > >
	Builds a PyIteratorRange from a ContainerRangeView. More...
struct	PyExportTraits< double >
	double is mapped to Python float type, which is also a C double. More...
struct	PyExportTraits< float >
	float is mapped to Python float type, which is a C double. More...
struct	PyExportTraits< FreeIndexedRangeView< SelfType, ValueType, SizeType, AtFunc, SizeFunc > >
	Builds a PyIteratorRange from a FreeIndexedRangeView. More...
struct	PyExportTraits< FreeRangeView< SelfType, ValueType, GetIterator > >
	Builds a PyIteratorRange from a FreeRangeView. More...
struct	PyExportTraits< IndexedRangeView< SelfType, ValueType, SizeType, AtMethod, SizeMethod > >
	Builds a PyIteratorRange from a IndexedRangeView. More...
struct	PyExportTraits< long double >
	long double is mapped to Python float type, which is a C double. More...
struct	PyExportTraits< MaybeNone< std::optional< T > > >
	MaybeNone<std::optional<T>> type-hints a type as T | MaybeNone More...
struct	PyExportTraits< MaybeNone< std::shared_ptr< T > > >
	MaybeNone<std::shared_ptr<T>> type-hints a type as T | MaybeNone More...
struct	PyExportTraits< MaybeNone< T * > >
	MaybeNone<T*> type-hints a type as T | MaybeNone More...
struct	PyExportTraits< MaybeNone< util::SharedPtr< T, S, C > > >
	MaybeNone<util::SharedPtr<T>> type-hints a type as T | MaybeNone More...
struct	PyExportTraits< MemberRangeView< SelfType, ValueType, GetIterator > >
	Builds a PyIteratorRange from a MemberRangeView. More...
struct	PyExportTraits< NoNone< std::shared_ptr< T > > >
	NoNone<std::shared_ptr<T>> type-hints as T and refuses None as value. More...
struct	PyExportTraits< NoNone< T * > >
	NoNone<T*> type-hints as T and refuses None as value. More...
struct	PyExportTraits< NoNone< util::SharedPtr< T, S, C > > >
	Type-hints NoNone<util::SharedPtr<T>> as T and refuses None as value. More...
struct	PyExportTraits< prim::Aabb2D< T, MMP > >
	Maps prim::Aabb2D<T> to a Python tuple of two tuples of two elements of type T. More...
struct	PyExportTraits< prim::Aabb3D< T, MMP > >
	Maps prim::Aabb3D<T> to a Python tuple of two tuples of three elements of type T. More...
struct	PyExportTraits< prim::ColorRGBA >
	Maps prim::ColorRGBA to a Python tuple of four elements of type float. More...
struct	PyExportTraits< prim::IndexTriangle >
	Maps prim::IndexTriangle to a Python tuple of three index vertices. More...
struct	PyExportTraits< prim::LineSegment2D< T, PP > >
	Maps prim::LineSegment2D<T> to a Python tuple of two tuples of two elements of type T. More...
struct	PyExportTraits< prim::LineSegment3D< T, PP > >
	Maps prim::LineSegment3D<T> to a Python tuple of two tuples of three elements of type T. More...
struct	PyExportTraits< prim::Point2D< T > >
	Maps prim::Point2D<T> to a Python tuple of two elements of type T. More...
struct	PyExportTraits< prim::Point3D< T > >
	Maps prim::Point3D<T> to a Python tuple of three elements of type T. More...
struct	PyExportTraits< prim::SimplePolygon2D< T, DP > >
	Maps prim::SimplePolygon2D<T> to a Python sequence of tuples of two elements of type T. More...
struct	PyExportTraits< prim::SimplePolygon3D< T, DP > >
	Maps prim::SimplePolygon3D<T> to a Python sequence of tuples of three elements of type T. More...
struct	PyExportTraits< prim::Transformation2D< T > >
	Maps prim::Transformation2D<T> to a Python tuple of three tuples of three elements of type T. More...
struct	PyExportTraits< prim::Transformation3D< T > >
	Maps prim::Transformation3D<T> to a Python tuple of four tuples of four elements of type T. More...
struct	PyExportTraits< prim::Vector2D< T > >
	Maps prim::Vector2D<T> to a Python tuple of two elements of type T. More...
struct	PyExportTraits< prim::Vector3D< T > >
	Maps prim::Vector3D<T> to a Python tuple of three elements of type T. More...
struct	PyExportTraits< prim::Vector4D< T > >
	Maps prim::Vector4D<T> to a Python tuple of four elements of type T. More...
struct	PyExportTraits< prim::XY >
	Maps prim::XY to a Python string literal "x" or "y". More...
struct	PyExportTraits< prim::XYZ >
	Maps prim::XYZ to a Python string literal "x", "y" or "z". More...
struct	PyExportTraits< prim::XYZW >
	Maps prim::XYZW to a Python string literal "x", "y", "z" or "w". More...
struct	PyExportTraits< PyIteratorRange * >
	Passes a PyIteratorRange to Python. More...
struct	PyExportTraits< Self< T > >
	Self<T> type-hints as Self. More...
struct	PyExportTraits< signed char >
	signed char is mapped to Python int More...
struct	PyExportTraits< signed int >
	signed int is mapped to Python int More...
struct	PyExportTraits< signed long >
	signed long is mapped to Python int More...
struct	PyExportTraits< signed short >
	signed short is mapped to Python int More...
struct	PyExportTraits< std::basic_string_view< T > >
	std::basic_string_view<T> is mapped to Python str More...
struct	PyExportTraits< std::chrono::duration< Rep, Period > >
	std::chrono::duration is mapped on datetime.timedelta by copy. More...
struct	PyExportTraits< std::chrono::file_clock::time_point >
	std::chrono::file_clock::time_point is mapped on a timezone-aware datetime.datetime instance by copy, in UTC. More...
struct	PyExportTraits< std::chrono::gps_clock::time_point >
	std::chrono::gps_clock::time_point is mapped on a timezone-aware datetime.datetime instance by copy, in UTC. More...
struct	PyExportTraits< std::chrono::tai_clock::time_point >
	std::chrono::tai_clock::time_point is mapped on a timezone-aware datetime.datetime instance by copy, in UTC. More...
struct	PyExportTraits< std::chrono::time_point< std::chrono::system_clock > >
	std::chrono::time_point<std::chrono::system_clock> is mapped on a timezone-unaware datetime.datetime instance by copy, in local time. More...
struct	PyExportTraits< std::chrono::utc_clock::time_point >
	std::chrono::utc_clock::time_point is mapped on a timezone-aware datetime.datetime instance by copy, in UTC. More...
struct	PyExportTraits< std::chrono::year_month_day >
	std::chrono::year_month_day is mapped on a datetime.date instance by copy. More...
struct	PyExportTraits< std::complex< T > >
	std::complex<T> is always mapped to Python complex type. More...
struct	PyExportTraits< std::function< R(Args...)> >
	Bidirectional wrapper between Callable objects and std::function. More...
struct	PyExportTraits< std::optional< T > >
	Uses None to represent a std::optional without value. More...
struct	PyExportTraits< std::pair< T1, T2 > >
	std::pair translates to a tuple by copy. More...
struct	PyExportTraits< std::shared_ptr< T > >
	std::shared_ptr assumes shadow types. More...
struct	PyExportTraits< std::tuple< T... > >
	std::tuple translates to a tuple by copy. More...
struct	PyExportTraits< std::u16string >
	UTF-16 std::u16string is mapped to str More...
struct	PyExportTraits< std::u32string >
	UTF-32 std::u32string is mapped to str More...
struct	PyExportTraits< std::unique_ptr< T, Deleter > >
	std::unique_ptr assumes shadow types More...
struct	PyExportTraits< TPyObjPtr >
	A shared PyObject pointer is mapped to Any in Python. More...
struct	PyExportTraits< unsigned char >
	unsigned char is mapped to Python int More...
struct	PyExportTraits< unsigned int >
	unsigned int is mapped to Python int More...
struct	PyExportTraits< unsigned long >
	unsigned long is mapped to Python int More...
struct	PyExportTraits< unsigned short >
	unsigned short is mapped to Python int More...
struct	PyExportTraits< util::Callback0 >
	Bidirectional mapping between util::Callback0 and a Python callable object. More...
struct	PyExportTraits< util::Callback10< P1, P2, P3, P4, P5, P6, P7, P8, P9, P10 > >
	Bidirectional mapping between util::Callback10 and a Python callable object. More...
struct	PyExportTraits< util::Callback11< P1, P2, P3, P4, P5, P6, P7, P8, P9, P10, P11 > >
	Bidirectional mapping between util::Callback11 and a Python callable object. More...
struct	PyExportTraits< util::Callback12< P1, P2, P3, P4, P5, P6, P7, P8, P9, P10, P11, P12 > >
	Bidirectional mapping between util::Callback12 and a Python callable object. More...
struct	PyExportTraits< util::Callback13< P1, P2, P3, P4, P5, P6, P7, P8, P9, P10, P11, P12, P13 > >
	Bidirectional mapping between util::Callback13 and a Python callable object. More...
struct	PyExportTraits< util::Callback14< P1, P2, P3, P4, P5, P6, P7, P8, P9, P10, P11, P12, P13, P14 > >
	Bidirectional mapping between util::Callback14 and a Python callable object. More...
struct	PyExportTraits< util::Callback15< P1, P2, P3, P4, P5, P6, P7, P8, P9, P10, P11, P12, P13, P14, P15 > >
	Bidirectional mapping between util::Callback15 and a Python callable object. More...
struct	PyExportTraits< util::Callback1< P1 > >
	Bidirectional mapping between util::Callback1 and a Python callable object. More...
struct	PyExportTraits< util::Callback2< P1, P2 > >
	Bidirectional mapping between util::Callback2 and a Python callable object. More...
struct	PyExportTraits< util::Callback3< P1, P2, P3 > >
	Bidirectional mapping between util::Callback3 and a Python callable object. More...
struct	PyExportTraits< util::Callback4< P1, P2, P3, P4 > >
	Bidirectional mapping between util::Callback4 and a Python callable object. More...
struct	PyExportTraits< util::Callback5< P1, P2, P3, P4, P5 > >
	Bidirectional mapping between util::Callback5 and a Python callable object. More...
struct	PyExportTraits< util::Callback6< P1, P2, P3, P4, P5, P6 > >
	Bidirectional mapping between util::Callback6 and a Python callable object. More...
struct	PyExportTraits< util::Callback7< P1, P2, P3, P4, P5, P6, P7 > >
	Bidirectional mapping between util::Callback7 and a Python callable object. More...
struct	PyExportTraits< util::Callback8< P1, P2, P3, P4, P5, P6, P7, P8 > >
	Bidirectional mapping between util::Callback8 and a Python callable object. More...
struct	PyExportTraits< util::Callback9< P1, P2, P3, P4, P5, P6, P7, P8, P9 > >
	Bidirectional mapping between util::Callback9 and a Python callable object. More...
struct	PyExportTraits< util::CallbackR0< R > >
	Bidirectional mapping between util::CallbackR0 and a Python callable object. More...
struct	PyExportTraits< util::CallbackR10< R, P1, P2, P3, P4, P5, P6, P7, P8, P9, P10 > >
	Bidirectional mapping between util::CallbackR10 and a Python callable object. More...
struct	PyExportTraits< util::CallbackR11< R, P1, P2, P3, P4, P5, P6, P7, P8, P9, P10, P11 > >
	Bidirectional mapping between util::CallbackR11 and a Python callable object. More...
struct	PyExportTraits< util::CallbackR12< R, P1, P2, P3, P4, P5, P6, P7, P8, P9, P10, P11, P12 > >
	Bidirectional mapping between util::CallbackR12 and a Python callable object. More...
struct	PyExportTraits< util::CallbackR13< R, P1, P2, P3, P4, P5, P6, P7, P8, P9, P10, P11, P12, P13 > >
	Bidirectional mapping between util::CallbackR13 and a Python callable object. More...
struct	PyExportTraits< util::CallbackR14< R, P1, P2, P3, P4, P5, P6, P7, P8, P9, P10, P11, P12, P13, P14 > >
	Bidirectional mapping between util::CallbackR14 and a Python callable object. More...
struct	PyExportTraits< util::CallbackR15< R, P1, P2, P3, P4, P5, P6, P7, P8, P9, P10, P11, P12, P13, P14, P15 > >
	Bidirectional mapping between util::CallbackR15 and a Python callable object. More...
struct	PyExportTraits< util::CallbackR1< R, P1 > >
	Bidirectional mapping between util::CallbackR1 and a Python callable object. More...
struct	PyExportTraits< util::CallbackR2< R, P1, P2 > >
	Bidirectional mapping between util::CallbackR2 and a Python callable object. More...
struct	PyExportTraits< util::CallbackR3< R, P1, P2, P3 > >
	Bidirectional mapping between util::CallbackR3 and a Python callable object. More...
struct	PyExportTraits< util::CallbackR4< R, P1, P2, P3, P4 > >
	Bidirectional mapping between util::CallbackR4 and a Python callable object. More...
struct	PyExportTraits< util::CallbackR5< R, P1, P2, P3, P4, P5 > >
	Bidirectional mapping between util::CallbackR5 and a Python callable object. More...
struct	PyExportTraits< util::CallbackR6< R, P1, P2, P3, P4, P5, P6 > >
	Bidirectional mapping between util::CallbackR6 and a Python callable object. More...
struct	PyExportTraits< util::CallbackR7< R, P1, P2, P3, P4, P5, P6, P7 > >
	Bidirectional mapping between util::CallbackR7 and a Python callable object. More...
struct	PyExportTraits< util::CallbackR8< R, P1, P2, P3, P4, P5, P6, P7, P8 > >
	Bidirectional mapping between util::CallbackR8 and a Python callable object. More...
struct	PyExportTraits< util::CallbackR9< R, P1, P2, P3, P4, P5, P6, P7, P8, P9 > >
	Bidirectional mapping between util::CallbackR9 and a Python callable object. More...
struct	PyExportTraits< util::SharedPtr< T, S, C > >
	SharedPtr assumes shadow types or PyObjectPlus types. More...
struct	PyExportTraitsCallback
	Helper class to implement PyExportTraits for Callback types. More...
struct	PyExportTraitsEnum
	Helper to specialise PyExportTraits for enumerations. More...
struct	PyExportTraitsFloat
	Helper class to create PyExportTraits for floating point numbers. More...
struct	PyExportTraitsMaybeNone
	Helper class to create PyExportTraits for MaybeNone wrapped types. More...
struct	PyExportTraitsNoNone
	Helper class to create PyExportTraits for NoNone wrapped types. More...
struct	PyExportTraitsSigned
	Helper class to create PyExportTraits for signed integers. More...
struct	PyExportTraitsUnsigned
	Helper class to create PyExportTraits for unsigned integers. More...
class	PyIteratorRange
	Python iterator object. More...
class	PyObjectCounter
	The recommended counter for the pyobject pointers, implementation of CounterPolicy concept. More...
class	PyObjectPlus
	PyObjectPlus. More...
struct	PyObjectPtr
	templated "typedef" to a python shared pointer More...
class	PyObjectStorage
	Recommended storage policy for single PyObject objects, implementation of StoragePolicy concept. More...
class	PythonException
	C++ exception type that holds a Python exception. More...
class	Self
	Wrapper to type-hint a return value as Self. More...
class	StrEnumDefinition
	Definition of an enum.StrEnum-derived enum type in Python. More...

Typedefs
typedef PyObjectPtr< PyObject >::Type	TPyObjPtr
	PyObjectPtr to a PyObject.
template<typename ShadoweeType>
using	ShadoweePtr
	Helper to get the pointer type holding the shadowee in a shadow object.

Enumerations
enum class	FlagBoundary { FlagBoundary::Keep , FlagBoundary::Strict , FlagBoundary::Conform }
	Defines the boundary behavior for enum.IntFlag-derived enums. More...

Functions
PyObject *	chainErrFormat (PyObject *exception, const char *format,...)
	Raise an explicitly chained Python exception.
PyObject *	chainErrFormatV (PyObject *exception, const char *format, va_list vargs)
	Raise an explicitly chained Python exception.
template<class T>
lass::util::SharedPtr< T, PyObjectStorage, PyObjectCounter >	fromNakedToSharedPtrCast (PyObject *object)
	fromNakedToSharedPtrCast.
template<class T>
PyObject *	fromSharedPtrToNakedCast (const util::SharedPtr< T, PyObjectStorage, PyObjectCounter > &object)
	fromSharedPtrToNakedCast.
template<typename Out, typename In>
Out	staticPyCast (const In &in)
	static_cast for python pointers
template<typename Out, typename In>
Out	dynamicPyCast (const In &in)
	dynamic_cast for python pointers
TPyObjPtr	getPyObjectByName (const std::string &iName)
	retrieve pointer to PyObject by its name in the script.
void	putenv (const std::string &key, const std::string &value)
	os.environ[key] = value
void	putenv (const char *key, const char *value)
	os.environ[key] = value
template<typename T>
auto	makeContainerRangeView (const ShadoweePtr< T > &self)
	Returns a ContainerRangeView iterating over self->begin() to self->end()
template<typename T, typename GetIterator>
auto	makeMemberRangeView (const ShadoweePtr< T > &self, GetIterator begin, GetIterator end)
	Returns a MemberRangeView iterating over (self->*begin)() and (self->*end)()
template<typename T, typename GetIterator>
auto	makeMemberRangeViewFactory (GetIterator begin, GetIterator end)
	Returns a callable creating a MemberRangeView iterating over (self->*begin)() to (self->*end)()
template<typename T, typename GetIterator>
auto	makeFreeRangeView (const ShadoweePtr< T > &self, GetIterator begin, GetIterator end)
	Returns a FreeRangeView iterating over begin(*self) and end(*self)
template<typename T, typename GetIterator>
auto	makeFreeRangeViewFactory (GetIterator begin, GetIterator end)
	Returns a callable creating a FreeRangeView iterating over begin(*self) and end(*self)
template<typename T, typename AtMethod, typename SizeMethod>
auto	makeIndexedRangeView (const ShadoweePtr< T > &self, AtMethod atMethod, SizeMethod sizeMethod)
	Returns a IndexedRangeView iterating over (self->*atMethod)(index) for index in 0 to (self->*sizeMethod)() - 1
template<typename T, typename AtMethod, typename SizeMethod>
auto	makeIndexedRangeViewFactory (AtMethod atMethod, SizeMethod sizeMethod)
	Returns callable that creates a IndexedRangeView iterating over (self->*atMethod)(index) for index in 0 to (self->*sizeMethod)() - 1
template<typename T, typename AtFunc, typename SizeFunc>
auto	makeFreeIndexedRangeView (const ShadoweePtr< T > &self, AtFunc atFunc, SizeFunc sizeFunc)
	Returns a FreeIndexedRangeView iterating over atFunc(*self, index) for index in 0 to sizeFunc(*self) - 1
template<typename T, typename AtFunc, typename SizeFunc>
auto	makeFreeIndexedRangeViewFactory (AtFunc atFunc, SizeFunc sizeFunc)
	Returns a callable that creates FreeIndexedRangeView iterating over atFunc(*self, index) for index in 0 to sizeFunc(*self) - 1