C API for Handwritten Code — SIP 4.13.2 Reference Guide

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# C API for Handwritten Code

In this section we describe the API that can be used by handwritten code in specification files.

`SIP_API_MAJOR_NR`

  This is a C preprocessor symbol that defines the major number of the SIP API. Its value is a number. There is no direct relationship between this and the SIP version number.

`SIP_API_MINOR_NR`

  This is a C preprocessor symbol that defines the minor number of the SIP API. Its value is a number. There is no direct relationship between this and the SIP version number.

`SIP_BLOCK_THREADS`

  This is a C preprocessor macro that will make sure the Python Global Interpreter Lock (GIL) is acquired. Python API calls must only be made when the GIL has been acquired. There must be a corresponding `SIP_UNBLOCK_THREADS` at the same lexical scope.

`SIP_NO_CONVERTORS`

  This is a flag used by various type convertors that suppresses the use of a type’s `%ConvertToTypeCode`.

`SIP_NOT_NONE`

  This is a flag used by various type convertors that causes the conversion to fail if the Python object being converted is `Py_None`.

`SIP_PROTECTED_IS_PUBLIC`

  New in version 4.10.

  This is a C preprocessor symbol that is defined automatically by the build system to specify that the generated code is being compiled with `protected` redefined as `public`. This allows handwritten code to determine if the generated helper functions for accessing protected C++ functions are available (see `%MethodCode`).

`SIP_SSIZE_T`

  This is a C preprocessor macro that is defined as `Py_ssize_t` for Python v2.5 and later, and as `int` for earlier versions of Python. It makes it easier to write PEP 353 compliant handwritten code.

`SIP_UNBLOCK_THREADS`

  This is a C preprocessor macro that will restore the Python Global Interpreter Lock (GIL) to the state it was prior to the corresponding `SIP_BLOCK_THREADS`.

`SIP_USE_PYCAPSULE`

  New in version 4.11.

  This is a C preprocessor symbol that is defined when `PyCapsule` objects are being used rather than the (now deprecated) `PyCObject` objects.

`SIP_VERSION`

  This is a C preprocessor symbol that defines the SIP version number represented as a 3 part hexadecimal number (e.g. v4.0.0 is represented as `0x040000`).

`SIP_VERSION_STR`

  This is a C preprocessor symbol that defines the SIP version number represented as a string. For development snapshots it will start with `snapshot-`.

sipErrorState `sipBadCallableArg`(int arg_nr, PyObject *arg)

  New in version 4.10.

  This is called from `%MethodCode` to raise a Python exception when an argument to a function, a C++ constructor or method is found to have an unexpected type. This should be used when the `%MethodCode` does additional type checking of the supplied arguments.

  Parameters: | arg_nr – the number of the argument. Arguments are numbered from 0 but are numbered from 1 in the detail of the exception. arg – the argument.
  Returns: | the value that should be assigned to `sipError`.

void `sipBadCatcherResult`(PyObject *method)

  This raises a Python exception when the result of a Python reimplementation of a C++ method doesn’t have the expected type. It is normally called by handwritten code specified with the `%VirtualCatcherCode` directive.

  Parameters: | method – the Python method and would normally be the supplied `sipMethod`.

void `sipBadLengthForSlice`(SIP_SSIZE_T seqlen, SIP_SSIZE_T slicelen)

  This raises a Python exception when the length of a slice object is inappropriate for a sequence-like object. It is normally called by handwritten code specified for `__setitem__()` methods.

  Parameters: | seqlen – the length of the sequence. slicelen – the length of the slice.

PyObject *`sipBuildResult`(int *iserr, const char *format, ...)

  This creates a Python object based on a format string and associated values in a similar way to the Python `Py_BuildValue()` function.

  Parameters: | iserr – if this is not `NULL` then the location it points to is set to a non-zero value. format – the string of format characters.
  Returns: | If there was an error then `NULL` is returned and a Python exception is raised.

  If the format string begins and ends with parentheses then a tuple of objects is created. If it contains more than one format character then parentheses must be specified.

  In the following description the first letter is the format character, the entry in parentheses is the Python object type that the format character will create, and the entry in brackets are the types of the C/C++ values to be passed.

  `a` (string) [char]
    Convert a C/C++ `char` to a Python v2 or v3 string object.
  `b` (boolean) [int]
    Convert a C/C++ `int` to a Python boolean.
  `c` (string/bytes) [char]
    Convert a C/C++ `char` to a Python v2 string object or a Python v3 bytes object.
  `d` (float) [double]
    Convert a C/C++ `double` to a Python floating point number.
  `e` (integer) [enum]
    Convert an anonymous C/C++ `enum` to a Python integer.
  `f` (float) [float]
    Convert a C/C++ `float` to a Python floating point number.
  `g` (string/bytes) [char *, `SIP_SSIZE_T`]
    Convert a C/C++ character array and its length to a Python v2 string object or a Python v3 bytes object. If the array is `NULL` then the length is ignored and the result is `Py_None`.
  `h` (integer) [short]
    Convert a C/C++ `short` to a Python integer.
  `i` (integer) [int]
    Convert a C/C++ `int` to a Python integer.
  `l` (long) [long]
    Convert a C/C++ `long` to a Python integer.
  `m` (long) [unsigned long]
    Convert a C/C++ `unsigned long` to a Python long.
  `n` (long) [long long]
    Convert a C/C++ `long long` to a Python long.
  `o` (long) [unsigned long long]
    Convert a C/C++ `unsigned long long` to a Python long.
  `r` (wrapped instance) [type *, `SIP_SSIZE_T`, const `sipTypeDef` *]
    Convert an array of C structures, C++ classes or mapped type instances to a Python tuple. Note that copies of the array elements are made.
  `s` (string/bytes) [char *]
    Convert a C/C++ `'\0'` terminated string to a Python v2 string object or a Python v3 bytes object. If the string pointer is `NULL` then the result is `Py_None`.
  `t` (long) [unsigned short]
    Convert a C/C++ `unsigned short` to a Python long.
  `u` (long) [unsigned int]
    Convert a C/C++ `unsigned int` to a Python long.
  `w` (unicode/string) [wchar_t]
    Convert a C/C++ wide character to a Python v2 unicode object or a Python v3 string object.
  `x` (unicode/string) [wchar_t *]
    Convert a C/C++ `L'\0'` terminated wide character string to a Python v2 unicode object or a Python v3 string object. If the string pointer is `NULL` then the result is `Py_None`.
  `A` (string) [char *]
    Convert a C/C++ `'\0'` terminated string to a Python v2 or v3 string object. If the string pointer is `NULL` then the result is `Py_None`.
  `B` (wrapped instance) [type *, `sipWrapperType` *, PyObject *]

    Deprecated since version 4.8: Use `N` instead.

    Convert a new C structure or a new C++ class instance to a Python class instance object. Ownership of the structure or instance is determined by the `PyObject *` argument. If it is `NULL` and the instance has already been wrapped then the ownership is unchanged. If it is `NULL` or `Py_None` then ownership will be with Python. Otherwise ownership will be with C/C++ and the instance associated with the `PyObject *` argument. The Python class is influenced by any applicable `%ConvertToSubClassCode` code.

  `C` (wrapped instance) [type *, `sipWrapperType` *, PyObject *]

    Deprecated since version 4.8: Use `D` instead.

    Convert a C structure or a C++ class instance to a Python class instance object. If the structure or class instance has already been wrapped then the result is a new reference to the existing class instance object. Ownership of the structure or instance is determined by the `PyObject *` argument. If it is `NULL` and the instance has already been wrapped then the ownership is unchanged. If it is `NULL` and the instance is newly wrapped then ownership will be with C/C++. If it is `Py_None` then ownership is transferred to Python via a call to `sipTransferBack()`. Otherwise ownership is transferred to C/C++ and the instance associated with the `PyObject *` argument via a call to `sipTransferTo()`. The Python class is influenced by any applicable `%ConvertToSubClassCode` code.

  `D` (wrapped instance) [type *, const `sipTypeDef` *, PyObject *]
    Convert a C structure, C++ class or mapped type instance to a Python object. If the instance has already been wrapped then the result is a new reference to the existing object. Ownership of the instance is determined by the `PyObject *` argument. If it is `NULL` and the instance has already been wrapped then the ownership is unchanged. If it is `NULL` and the instance is newly wrapped then ownership will be with C/C++. If it is `Py_None` then ownership is transferred to Python via a call to `sipTransferBack()`. Otherwise ownership is transferred to C/C++ and the instance associated with the `PyObject *` argument via a call to `sipTransferTo()`. The Python class is influenced by any applicable `%ConvertToSubClassCode` code.
  `E` (wrapped enum) [enum, PyTypeObject *]

    Deprecated since version 4.8: Use `F` instead.

    Convert a named C/C++ `enum` to an instance of the corresponding Python named enum type.

  `F` (wrapped enum) [enum, `sipTypeDef` *]
    Convert a named C/C++ `enum` to an instance of the corresponding Python named enum type.
  `G` (unicode) [wchar_t *, `SIP_SSIZE_T`]
    Convert a C/C++ wide character array and its length to a Python unicode object. If the array is `NULL` then the length is ignored and the result is `Py_None`.
  `L` (integer) [char]

    New in version 4.12.

    Convert a C/C++ `char` to a Python integer.

  `M` (long) [unsigned char]

    New in version 4.12.

    Convert a C/C++ `unsigned char` to a Python long.

  `N` (wrapped instance) [type *, `sipTypeDef` *, PyObject *]
    Convert a new C structure, C++ class or mapped type instance to a Python object. Ownership of the instance is determined by the `PyObject *` argument. If it is `NULL` and the instance has already been wrapped then the ownership is unchanged. If it is `NULL` or `Py_None` then ownership will be with Python. Otherwise ownership will be with C/C++ and the instance associated with the `PyObject *` argument. The Python class is influenced by any applicable `%ConvertToSubClassCode` code.
  `R` (object) [PyObject *]
    The result is value passed without any conversions. The reference count is unaffected, i.e. a reference is taken.
  `S` (object) [PyObject *]
    The result is value passed without any conversions. The reference count is incremented.
  `V` (sip.voidptr) [void *]
    Convert a C/C++ `void *` Python `sip.voidptr` object.

PyObject *`sipCallMethod`(int *iserr, PyObject *method, const char *format, ...)

  This calls a Python method passing a tuple of arguments based on a format string and associated values in a similar way to the Python `PyObject_CallObject()` function.

  Parameters: | iserr – if this is not `NULL` then the location it points to is set to a non-zero value if there was an error. method – the Python bound method to call. format – the string of format characters (see `sipBuildResult()`).
  Returns: | If there was an error then `NULL` is returned and a Python exception is raised.

  It is normally called by handwritten code specified with the `%VirtualCatcherCode` directive with method being the supplied `sipMethod`.

int `sipCanConvertToEnum`(PyObject *obj, const sipTypeDef *td)

  This checks if a Python object can be converted to a named enum.

  Parameters: | obj – the Python object. td – the enum’s generated type structure.
  Returns: | a non-zero value if the object can be converted.

int `sipCanConvertToInstance`(PyObject *obj, sipWrapperType *type, int flags)

  Deprecated since version 4.8: Use `sipCanConvertToType()` instead.

  This checks if a Python object can be converted to an instance of a C structure or C++ class.

  Parameters: | obj – the Python object. type – the C/C++ type’s generated type object. flags – any combination of the `SIP_NOT_NONE` and `SIP_NO_CONVERTORS` flags.
  Returns: | a non-zero value if the object can be converted.

int `sipCanConvertToMappedType`(PyObject *obj, const sipMappedType *mt, int flags)

  Deprecated since version 4.8: Use `sipCanConvertToType()` instead.

  This checks if a Python object can be converted to an instance of a C structure or C++ class which has been implemented as a mapped type.

  Parameters: | obj – the Python object. mt – the opaque structure returned by `sipFindMappedType()`. flags – this may be the `SIP_NOT_NONE` flag.
  Returns: | a non-zero value if the object can be converted.

int `sipCanConvertToType`(PyObject *obj, const sipTypeDef *td, int flags)

  This checks if a Python object can be converted to an instance of a C structure, C++ class or mapped type.

  Parameters: | obj – the Python object. td – the C/C++ type’s generated type structure. flags – any combination of the `SIP_NOT_NONE` and `SIP_NO_CONVERTORS` flags.
  Returns: | a non-zero value if the object can be converted.

PyObject *`sipClassName`(PyObject *obj)

  Deprecated since version 4.8: Use the following instead:

  > PyString_FromString(obj->ob_type->tp_name)

  This gets the class name of a wrapped instance as a Python string. It comes with a reference.

  Parameters: | obj – the wrapped instance.
  Returns: | the name of the instance’s class.

PyObject *`sipConvertFromConstVoidPtr`(const void *cpp)

  This creates a `sip.voidptr` object for a memory address. The object will not be writeable and has no associated size.

  Parameters: | cpp – the memory address.
  Returns: | the `sip.voidptr` object.

PyObject *`sipConvertFromConstVoidPtrAndSize`(const void *cpp, SIP_SSIZE_T size)

  This creates a `sip.voidptr` object for a memory address. The object will not be writeable and can be used as an immutable buffer object.

  Parameters: | cpp – the memory address. size – the size associated with the address.
  Returns: | the `sip.voidptr` object.

PyObject *`sipConvertFromEnum`(int eval, const sipTypeDef *td)

  This converts a named C/C++ `enum` to an instance of the corresponding generated Python type.

  Parameters: | eval – the enumerated value to convert. td – the enum’s generated type structure.
  Returns: | the Python object.

PyObject *`sipConvertFromInstance`(void *cpp, sipWrapperType *type, PyObject *transferObj)

  Deprecated since version 4.8: Use `sipConvertFromType()` instead.

  This converts a C structure or a C++ class instance to an instance of the corresponding generated Python type.

  Parameters: | cpp – the C/C++ instance. type – the type’s generated type object. transferObj – this controls the ownership of the returned value.
  Returns: | the Python object.

  If the C/C++ instance has already been wrapped then the result is a new reference to the existing class instance object.

  If transferObj is `NULL` and the instance has already been wrapped then the ownership is unchanged.

  If transferObj is `NULL` and the instance is newly wrapped then ownership will be with C/C++.

  If transferObj is `Py_None` then ownership is transferred to Python via a call to `sipTransferBack()`.

  Otherwise ownership is transferred to C/C++ and the instance associated with transferObj via a call to `sipTransferTo()`.

  The Python type is influenced by any applicable `%ConvertToSubClassCode` code.

PyObject *`sipConvertFromMappedType`(void *cpp, const sipMappedType *mt, PyObject *transferObj)

  Deprecated since version 4.8: Use `sipConvertFromType()` instead.

  This converts a C structure or a C++ class instance wrapped as a mapped type to an instance of the corresponding generated Python type.

  Parameters: | cpp – the C/C++ instance. mt – the opaque structure returned by `sipFindMappedType()`. transferObj – this controls the ownership of the returned value.
  Returns: | the Python object.

  If transferObj is `NULL` then the ownership is unchanged.

  If transferObj is `Py_None` then ownership is transferred to Python via a call to `sipTransferBack()`.

  Otherwise ownership is transferred to C/C++ and the instance associated with transferObj argument via a call to `sipTransferTo()`.

PyObject *`sipConvertFromNamedEnum`(int eval, PyTypeObject *type)

  Deprecated since version 4.8: Use `sipConvertFromEnum()` instead.

  This converts a named C/C++ `enum` to an instance of the corresponding generated Python type.

  Parameters: | eval – the enumerated value to convert. type – the enum’s generated type object.
  Returns: | the Python object.

PyObject *`sipConvertFromNewInstance`(void *cpp, sipWrapperType *type, PyObject *transferObj)

  Deprecated since version 4.8: Use `sipConvertFromNewType()` instead.

  This converts a new C structure or a C++ class instance to an instance of the corresponding generated Python type.

  Parameters: | cpp – the C/C++ instance. type – the type’s generated type object. transferObj – this controls the ownership of the returned value.
  Returns: | the Python object.

  If transferObj is `NULL` or `Py_None` then ownership will be with Python.

  Otherwise ownership will be with C/C++ and the instance associated with transferObj.

  The Python type is influenced by any applicable `%ConvertToSubClassCode` code.

PyObject *`sipConvertFromNewType`(void *cpp, const sipTypeDef *td, PyObject *transferObj)

  This converts a new C structure or a C++ class instance to an instance of the corresponding generated Python type.

  Parameters: | cpp – the C/C++ instance. td – the type’s generated type structure. transferObj – this controls the ownership of the returned value.
  Returns: | the Python object.

  If transferObj is `NULL` or `Py_None` then ownership will be with Python.

  Otherwise ownership will be with C/C++ and the instance associated with transferObj.

  The Python type is influenced by any applicable `%ConvertToSubClassCode` code.

SIP_SSIZE_T `sipConvertFromSequenceIndex`(SIP_SSIZE_T idx, SIP_SSIZE_T len)

  This converts a Python sequence index (i.e. where a negative value refers to the offset from the end of the sequence) to a C/C++ array index. If the index was out of range then a negative value is returned and a Python exception raised.

  Parameters: | idx – the sequence index. len – the length of the sequence.
  Returns: | the unsigned array index.

int `sipConvertFromSliceObject`(PyObject *slice, SIP_SSIZE_T length, SIP_SSIZE_T *start, SIP_SSIZE_T *stop, SIP_SSIZE_T *step, SIP_SSIZE_T *slicelength)

  This is a thin wrapper around the Python `PySlice_GetIndicesEx()` function provided to make it easier to write handwritten code that is compatible with SIP v3.x and versions of Python earlier that v2.3.

PyObject *`sipConvertFromType`(void *cpp, const sipTypeDef *td, PyObject *transferObj)

  This converts a C structure or a C++ class instance to an instance of the corresponding generated Python type.

  Parameters: | cpp – the C/C++ instance. td – the type’s generated type structure. transferObj – this controls the ownership of the returned value.
  Returns: | the Python object.

  If the C/C++ instance has already been wrapped then the result is a new reference to the existing object.

  If transferObj is `NULL` and the instance has already been wrapped then the ownership is unchanged.

  If transferObj is `NULL` and the instance is newly wrapped then ownership will be with C/C++.

  If transferObj is `Py_None` then ownership is transferred to Python via a call to `sipTransferBack()`.

  Otherwise ownership is transferred to C/C++ and the instance associated with transferObj via a call to `sipTransferTo()`.

  The Python class is influenced by any applicable `%ConvertToSubClassCode` code.

PyObject *`sipConvertFromVoidPtr`(void *cpp)

  This creates a `sip.voidptr` object for a memory address. The object will be writeable but has no associated size.

  Parameters: | cpp – the memory address.
  Returns: | the `sip.voidptr` object.

PyObject *`sipConvertFromVoidPtrAndSize`(void *cpp, SIP_SSIZE_T size)

  This creates a `sip.voidptr` object for a memory address. The object will be writeable and can be used as a mutable buffer object.

  Parameters: | cpp – the memory address. size – the size associated with the address.
  Returns: | the `sip.voidptr` object.

void *`sipConvertToInstance`(PyObject *obj, sipWrapperType *type, PyObject *transferObj, int flags, int *state, int *iserr)

  Deprecated since version 4.8: Use `sipConvertToType()` instead.

  This converts a Python object to an instance of a C structure or C++ class assuming that a previous call to `sipCanConvertToInstance()` has been successful.

  Parameters: | obj – the Python object. type – the type’s generated type object. transferObj – this controls any ownership changes to obj. flags – any combination of the `SIP_NOT_NONE` and `SIP_NO_CONVERTORS` flags. state – the state of the returned C/C++ instance is returned via this pointer. iserr – the error flag is passed and updated via this pointer.
  Returns: | the C/C++ instance.

  If transferObj is `NULL` then the ownership is unchanged.

  If transferObj is `Py_None` then ownership is transferred to Python via a call to `sipTransferBack()`.

  Otherwise ownership is transferred to C/C++ and obj associated with transferObj via a call to `sipTransferTo()`.

  If state is not `NULL` then the location it points to is set to describe the state of the returned C/C++ instance and is the value returned by any `%ConvertToTypeCode`. The calling code must then release the value at some point to prevent a memory leak by calling `sipReleaseInstance()`.

  If there is an error then the location iserr points to is set to a non-zero value. If it was initially a non-zero value then the conversion isn’t attempted in the first place. (This allows several calls to be made that share the same error flag so that it only needs to be tested once rather than after each call.)

void *`sipConvertToMappedType`(PyObject *obj, const sipMappedType *mt, PyObject *transferObj, int flags, int *state, int *iserr)

  Deprecated since version 4.8: Use `sipConvertToType()` instead.

  This converts a Python object to an instance of a C structure or C++ class that is implemented as a mapped type assuming that a previous call to `sipCanConvertToMappedType()` has been successful.

  Parameters: | obj – the Python object. mt – the opaque structure returned by `sipFindMappedType()`. transferObj – this controls any ownership changes to obj. flags – this may be the `SIP_NOT_NONE` flag. state – the state of the returned C/C++ instance is returned via this pointer. iserr – the error flag is passed and updated via this pointer.
  Returns: | the C/C++ instance.

  If transferObj is `NULL` then the ownership is unchanged.

  If transferObj is `Py_None` then ownership is transferred to Python via a call to `sipTransferBack()`.

  Otherwise ownership is transferred to C/C++ and obj associated with transferObj via a call to `sipTransferTo()`.

  If state is not `NULL` then the location it points to is set to describe the state of the returned C/C++ instance and is the value returned by any `%ConvertToTypeCode`. The calling code must then release the value at some point to prevent a memory leak by calling `sipReleaseMappedType()`.

  If there is an error then the location iserr points to is set to a non-zero value. If it was initially a non-zero value then the conversion isn’t attempted in the first place. (This allows several calls to be made that share the same error flag so that it only needs to be tested once rather than after each call.)

void *`sipConvertToType`(PyObject *obj, const sipTypeDef *td, PyObject *transferObj, int flags, int *state, int *iserr)

  This converts a Python object to an instance of a C structure, C++ class or mapped type assuming that a previous call to `sipCanConvertToType()` has been successful.

  Parameters: | obj – the Python object. td – the type’s generated type structure. transferObj – this controls any ownership changes to obj. flags – any combination of the `SIP_NOT_NONE` and `SIP_NO_CONVERTORS` flags. state – the state of the returned C/C++ instance is returned via this pointer. iserr – the error flag is passed and updated via this pointer.
  Returns: | the C/C++ instance.

  If transferObj is `NULL` then the ownership is unchanged. If it is `Py_None` then ownership is transferred to Python via a call to `sipTransferBack()`.

  Otherwise ownership is transferred to C/C++ and obj associated with transferObj via a call to `sipTransferTo()`.

  If state is not `NULL` then the location it points to is set to describe the state of the returned C/C++ instance and is the value returned by any `%ConvertToTypeCode`. The calling code must then release the value at some point to prevent a memory leak by calling `sipReleaseType()`.

  If there is an error then the location iserr points to is set to a non-zero value. If it was initially a non-zero value then the conversion isn’t attempted in the first place. (This allows several calls to be made that share the same error flag so that it only needs to be tested once rather than after each call.)

void *`sipConvertToVoidPtr`(PyObject *obj)

  This converts a Python object to a memory address. `PyErr_Occurred()` must be used to determine if the conversion was successful.

  Parameters: | obj – the Python object which may be `Py_None`, a `sip.voidptr` or a `PyCObject`.
  Returns: | the memory address.

int `sipExportSymbol`(const char *name, void *sym)

  Python does not allow extension modules to directly access symbols in another extension module. This exports a symbol, referenced by a name, that can subsequently be imported, using `sipImportSymbol()`, by another module.

  Parameters: | name – the name of the symbol. sym – the value of the symbol.
  Returns: | 0 if there was no error. A negative value is returned if name is already associated with a symbol or there was some other error.

sipWrapperType *`sipFindClass`(const char *type)

  Deprecated since version 4.8: Use `sipFindType()` instead.

  This returns a pointer to the generated type object <ref-type-objects corresponding to a C/C++ type.

  Parameters: | type – the C/C++ declaration of the type.
  Returns: | the generated type object. This will not change and may be saved in a static cache. `NULL` is returned if the C/C++ type doesn’t exist.

const sipMappedType *`sipFindMappedType`(const char *type)

  Deprecated since version 4.8: Use `sipFindType()` instead.

  This returns a pointer to an opaque structure describing a mapped type.

  Parameters: | type – the C/C++ declaration of the type.
  Returns: | the opaque structure. This will not change and may be saved in a static cache. `NULL` is returned if the C/C++ type doesn’t exist.

PyTypeObject *`sipFindNamedEnum`(const char *type)

  Deprecated since version 4.8: Use `sipFindType()` instead.

  This returns a pointer to the generated Python type object corresponding to a named C/C++ enum.

  Parameters: | type – the C/C++ declaration of the enum.
  Returns: | the generated Python type object. This will not change and may be saved in a static cache. `NULL` is returned if the C/C++ enum doesn’t exist.

const sipTypeDef *`sipFindType`(const char *type)

  This returns a pointer to the generated type structure corresponding to a C/C++ type.

  Parameters: | type – the C/C++ declaration of the type.
  Returns: | the generated type structure. This will not change and may be saved in a static cache. `NULL` is returned if the C/C++ type doesn’t exist.

void *`sipForceConvertToInstance`(PyObject *obj, sipWrapperType *type, PyObject *transferObj, int flags, int *state, int *iserr)

  Deprecated since version 4.8: Use `sipForceConvertToType()` instead.

  This converts a Python object to an instance of a C structure or C++ class by calling `sipCanConvertToInstance()` and, if it is successfull, calling `sipConvertToInstance()`.

  See `sipConvertToInstance()` for a full description of the arguments.

void *`sipForceConvertToMappedType`(PyObject *obj, const sipMappedType *mt, PyObject *transferObj, int flags, int *state, int *iserr)

  Deprecated since version 4.8: Use `sipForceConvertToType()` instead.

  This converts a Python object to an instance of a C structure or C++ class which has been implemented as a mapped type by calling `sipCanConvertToMappedType()` and, if it is successfull, calling `sipConvertToMappedType()`.

  See `sipConvertToMappedType()` for a full description of the arguments.

void *`sipForceConvertToType`(PyObject *obj, const sipTypeDef *td, PyObject *transferObj, int flags, int *state, int *iserr)

  This converts a Python object to an instance of a C structure, C++ class or mapped type by calling `sipCanConvertToType()` and, if it is successfull, calling `sipConvertToType()`.

  See `sipConvertToType()` for a full description of the arguments.

void `sipFree`(void *mem)

  This returns an area of memory allocated by `sipMalloc()` to the heap.

  Parameters: | mem – the memory address.

void *`sipGetAddress`(sipSimpleWrapper *obj)

  New in version 4.12.

  This returns the address of the C structure or C++ class instance wrapped by a Python object.

  Parameters: | obj – the Python object.
  Returns: | the address of the C/C++ instance

PyObject *`sipGetPyObject`(void *cppptr, const sipTypeDef *td)

  This returns a borrowed reference to the Python object for a C structure or C++ class instance.

  Parameters: | cppptr – the pointer to the C/C++ instance. td – the generated type structure corresponding to the C/C++ type.
  Returns: | the Python object or `NULL` (and no exception is raised) if the C/C++ instance hasn’t been wrapped.

int `sipGetState`(PyObject *transferObj)

  The `%ConvertToTypeCode` directive requires that the provided code returns an `int` describing the state of the converted value. The state usually depends on any transfers of ownership that have been requested. This is a convenience function that returns the correct state when the converted value is a temporary.

  Parameters: | transferObj – the object that describes the requested transfer of ownership.
  Returns: | the state of the converted value.

PyObject *`sipGetWrapper`(void *cppptr, sipWrapperType *type)

  Deprecated since version 4.8: Use `sipGetPyObject()` instead.

  This returns a borrowed reference to the wrapped instance object for a C structure or C++ class instance.

  Parameters: | cppptr – the pointer to the C/C++ instance. type – the generated type object corresponding to the C/C++ type.
  Returns: | the Python object or `NULL` (and no exception is raised) if the C/C++ instance hasn’t been wrapped.

void *`sipImportSymbol`(const char *name)

  Python does not allow extension modules to directly access symbols in another extension module. This imports a symbol, referenced by a name, that has previously been exported, using `sipExportSymbol()`, by another module.

  Parameters: | name – the name of the symbol.
  Returns: | the value of the symbol. `NULL` is returned if there is no such symbol.

`sipIntTypeClassMap`

  Deprecated since version 4.8.

  This C structure is used with `sipMapIntToClass()` to define a mapping between integer based RTTI and generated type objects. The structure elements are as follows.

  int `typeInt`

    The integer RTTI.

  sipWrapperType **`pyType.`

    A pointer to the corresponding generated type object.

int `sipIsAPIEnabled`(const char *name, int from, int to)

  New in version 4.9.

  This checks to see if the current version number of an API falls within a given range. See Managing Incompatible APIs for more detail.

  Parameters: | name – the name of the API. from – the lower bound of the range. For the API to be enabled its version number must be greater than or equal to from. If from is 0 then this check isn’t made. to – the upper bound of the range. For the API to be enabled its version number must be less than to. If to is 0 then this check isn’t made.
  Returns: | a non-zero value if the API is enabled.

unsigned long `sipLong_AsUnsignedLong`(PyObject *obj)

  This function is a thin wrapper around `PyLong_AsUnsignedLong()` that works around a bug in Python v2.3.x and earlier when converting integer objects.

void *`sipMalloc`(size_t nbytes)

  This allocates an area of memory on the heap using the Python `PyMem_Malloc()` function. The memory is freed by calling `sipFree()`.

  Parameters: | nbytes – the number of bytes to allocate.
  Returns: | the memory address. If there was an error then `NULL` is returned and a Python exception raised.

sipWrapperType *`sipMapIntToClass`(int type, const sipIntTypeClassMap *map, int maplen)

  Deprecated since version 4.8.

  This can be used in `%ConvertToSubClassCode` code as a convenient way of converting integer based RTTI to the corresponding generated type object.

  Parameters: | type – the integer RTTI. map – the table of known RTTI and the corresponding type objects (see `sipIntTypeClassMap`). The entries in the table must be sorted in ascending order of RTTI. maplen – the number of entries in the table.
  Returns: | the corresponding type object, or `NULL` if type wasn’t in map.

sipWrapperType *`sipMapStringToClass`(char *type, const sipStringTypeClassMap *map, int maplen)

  Deprecated since version 4.8.

  This can be used in `%ConvertToSubClassCode` code as a convenient way of converting `'\0'` terminated string based RTTI to the corresponding generated type object.

  Parameters: | type – the string RTTI. map – the table of known RTTI and the corresponding type objects (see `sipStringTypeClassMap`). The entries in the table must be sorted in ascending order of RTTI. maplen – the number of entries in the table.
  Returns: | the corresponding type object, or `NULL` if type wasn’t in map.

int `sipParseResult`(int *iserr, PyObject *method, PyObject *result, const char *format, ...)

  This converts a Python object (usually returned by a method) to C/C++ based on a format string and associated values in a similar way to the Python `PyArg_ParseTuple()` function.

  Parameters: | iserr – if this is not `NULL` then the location it points to is set to a non-zero value if there was an error. method – the Python method that returned result. result – the Python object returned by method. format – the format string.
  Returns: | 0 if there was no error. Otherwise a negative value is returned, and an exception raised.

  This is normally called by handwritten code specified with the `%VirtualCatcherCode` directive with method being the supplied `sipMethod` and result being the value returned by `sipCallMethod()`.

  If format begins and ends with parentheses then result must be a Python tuple and the rest of format is applied to the tuple contents.

  In the following description the first letter is the format character, the entry in parentheses is the Python object type that the format character will convert, and the entry in brackets are the types of the C/C++ values to be passed.

  `ae` (object) [char *]
    Convert a Python string-like object of length 1 to a C/C++ `char` according to the encoding `e`. `e` can either be `A` for ASCII, `L` for Latin-1, or `8` for UTF-8. For Python v2 the object may be either a string or a unicode object that can be encoded. For Python v3 the object may either be a bytes object or a string object that can be encoded. An object that supports the buffer protocol may also be used.
  `b` (integer) [bool *]
    Convert a Python integer to a C/C++ `bool`.
  `c` (string/bytes) [char *]
    Convert a Python v2 string object or a Python v3 bytes object of length 1 to a C/C++ `char`.
  `d` (float) [double *]
    Convert a Python floating point number to a C/C++ `double`.
  `e` (integer) [enum *]
    Convert a Python integer to an anonymous C/C++ `enum`.
  `f` (float) [float *]
    Convert a Python floating point number to a C/C++ `float`.
  `g` (string/bytes) [const char **, `SIP_SSIZE_T` *]
    Convert a Python v2 string object or a Python v3 bytes object to a C/C++ character array and its length. If the Python object is `Py_None` then the array and length are `NULL` and zero respectively.
  `h` (integer) [short *]
    Convert a Python integer to a C/C++ `short`.
  `i` (integer) [int *]
    Convert a Python integer to a C/C++ `int`.
  `l` (long) [long *]
    Convert a Python long to a C/C++ `long`.
  `m` (long) [unsigned long *]
    Convert a Python long to a C/C++ `unsigned long`.
  `n` (long) [long long *]
    Convert a Python long to a C/C++ `long long`.
  `o` (long) [unsigned long long *]
    Convert a Python long to a C/C++ `unsigned long long`.
  `s` (string/bytes) [const char **]

    Deprecated since version 4.8: Use `B` instead.

    Convert a Python v2 string object or a Python v3 bytes object to a C/C++ `'\0'` terminated string. If the Python object is `Py_None` then the string is `NULL`.

  `t` (long) [unsigned short *]
    Convert a Python long to a C/C++ `unsigned short`.
  `u` (long) [unsigned int *]
    Convert a Python long to a C/C++ `unsigned int`.
  `w` (unicode/string) [wchar_t *]
    Convert a Python v2 string or unicode object or a Python v3 string object of length 1 to a C/C++ wide character.
  `x` (unicode/string) [wchar_t **]
    Convert a Python v2 string or unicode object or a Python v3 string object to a C/C++ `L'\0'` terminated wide character string. If the Python object is `Py_None` then the string is `NULL`.
  `Ae` (object) [int, const char **]
    Convert a Python string-like object to a C/C++ `'\0'` terminated string according to the encoding `e`. `e` can either be `A` for ASCII, `L` for Latin-1, or `8` for UTF-8. If the Python object is `Py_None` then the string is `NULL`. The integer uniquely identifies the object in the context defined by the `S` format character and allows an extra reference to the object to be kept to ensure that the string remains valid. For Python v2 the object may be either a string or a unicode object that can be encoded. For Python v3 the object may either be a bytes object or a string object that can be encoded. An object that supports the buffer protocol may also be used.
  `B` (string/bytes) [int, const char **]
    Convert a Python v2 string object or a Python v3 bytes object to a C/C++ `'\0'` terminated string. If the Python object is `Py_None` then the string is `NULL`. The integer uniquely identifies the object in the context defined by the `S` format character and allows an extra reference to the object to be kept to ensure that the string remains valid.
  `Cf` (wrapped class) [`sipWrapperType` *, int *, void **]

    Deprecated since version 4.8: Use `Hf` instead.

    Convert a Python object to a C structure or a C++ class instance and return its state as described in `sipConvertToInstance()`. `f` is a combination of the following flags encoded as an ASCII character by adding `0` to the combined value:

    > 0x01 disallows the conversion of `Py_None` to `NULL`

    > 0x02 implements the `Factory` and `TransferBack`
    >   annotations
    > 0x04 suppresses the return of the state of the returned C/C++
    >   instance. Note that the `int *` used to return the state is not passed if this flag is specified.

  `Df` (wrapped instance) [const `sipTypeDef` *, int *, void **]

    Deprecated since version 4.10.1: Use `Hf` instead.

    Convert a Python object to a C structure, C++ class or mapped type instance and return its state as described in `sipConvertToType()`. `f` is a combination of the following flags encoded as an ASCII character by adding `0` to the combined value:

    > 0x01 disallows the conversion of `Py_None` to `NULL`

    > 0x02 implements the `Factory` and `TransferBack`
    >   annotations
    > 0x04 suppresses the return of the state of the returned C/C++
    >   instance. Note that the `int *` used to return the state is not passed if this flag is specified.

  `E` (wrapped enum) [PyTypeObject *, enum *]

    Deprecated since version 4.8: Use `F` instead.

    Convert a Python named enum type to the corresponding C/C++ `enum`.

  `F` (wrapped enum) [`sipTypeDef` *, enum *]
    Convert a Python named enum type to the corresponding C/C++ `enum`.
  `G` (unicode/string) [wchar_t **, `SIP_SSIZE_T` *]
    Convert a Python v2 string or unicode object or a Python v3 string object to a C/C++ wide character array and its length. If the Python object is `Py_None` then the array and length are `NULL` and zero respectively.
  `Hf` (wrapped instance) [const `sipTypeDef` *, int *, void **]

    Convert a Python object to a C structure, C++ class or mapped type instance as described in `sipConvertToType()`. `f` is a combination of the following flags encoded as an ASCII character by adding `0` to the combined value:

    > 0x01 disallows the conversion of `Py_None` to `NULL`

    > 0x02 implements the `Factory` and `TransferBack`
    >   annotations

    > 0x04 returns a copy of the C/C++ instance.

  `L` (integer) [signed char *]

    New in version 4.12.

    Convert a Python integer to a C/C++ `signed char`.

  `M` (long) [unsigned char *]

    New in version 4.12.

    Convert a Python long to a C/C++ `unsigned char`.

  `N` (object) [PyTypeObject *, :PyObject **]
    A Python object is checked to see if it is a certain type and then returned without any conversions. The reference count is incremented. The Python object may be `Py_None`.
  `O` (object) [PyObject **]
    A Python object is returned without any conversions. The reference count is incremented.
  `S` [`sipSimpleWrapper` *]
    This format character, if used, must be the first. It is used with other format characters to define a context and doesn’t itself convert an argument.
  `T` (object) [PyTypeObject *, PyObject **]
    A Python object is checked to see if it is a certain type and then returned without any conversions. The reference count is incremented. The Python object may not be `Py_None`.
  `V` (`sip.voidptr`) [void *]
    Convert a Python `sip.voidptr` object to a C/C++ `void *`.
  `Z` (object) []
    Check that a Python object is `Py_None`. No value is returned.

int `sipRegisterAttributeGetter`(const sipTypeDef *td, sipAttrGetterFunc getter)

  This registers a handler that will called just before SIP needs to get an attribute from a wrapped type’s dictionary for the first time. The handler must then populate the type’s dictionary with any lazy attributes.

  Parameters: | td – the optional generated type structure that determines which types the handler will be called for. getter – the handler function.
  Returns: | 0 if there was no error, otherwise -1 is returned.

  If td is not `NULL` then the handler will only be called for types with that type or that are sub-classed from it. Otherwise the handler will be called for all types.

  A handler has the following signature.

  int handler(const `sipTypeDef` *td, PyObject *dict)

  > td is the generated type definition of the type whose dictionary is to be populated.

  > dict is the dictionary to be populated.

  > 0 if there was no error, otherwise -1 is returned.

  See the section Lazy Type Attributes for more details.

int `sipRegisterPyType`(PyTypeObject *type)

  This registers a Python type object that can be used as the meta-type or super-type of a wrapped C++ type.

  Parameters: | type – the type object.
  Returns: | 0 if there was no error, otherwise -1 is returned.

  See the section Types and Meta-types for more details.

void `sipReleaseInstance`(void *cpp, sipWrapperType *type, int state)

  Deprecated since version 4.8: Use `sipReleaseType()` instead.

  This destroys a wrapped C/C++ instance if it was a temporary instance. It is called after a call to either `sipConvertToInstance()` or `sipForceConvertToInstance()`.

  Parameters: | cpp – the C/C++ instance. type – the type’s generated type object. state – describes the state of the C/C++ instance.

void `sipReleaseMappedType`(void *cpp, const sipMappedType *mt, int state)

  Deprecated since version 4.8: Use `sipReleaseType()` instead.

  This destroys a wrapped C/C++ mapped type if it was a temporary instance. It is called after a call to either `sipConvertToMappedType()` or `sipForceConvertToMappedType()`.

  Parameters: | cpp – the C/C++ instance. mt – the opaque structure returned by `sipFindMappedType()`. state – describes the state of the C/C++ instance.

void `sipReleaseType`(void *cpp, const sipTypeDef *td, int state)

  This destroys a wrapped C/C++ or mapped type instance if it was a temporary instance. It is called after a call to either `sipConvertToType()` or `sipForceConvertToType()`.

  Parameters: | cpp – the C/C++ instance. td – the type’s generated type structure. state – describes the state of the C/C++ instance.

const char *`sipResolveTypedef`(const char *name)

  This returns the value of a C/C++ typedef.

  Parameters: | name – the name of the typedef.
  Returns: | the value of the typedef or `NULL` if there was no such typedef.

`sipSimpleWrapper`

  This is a C structure that represents a Python wrapped instance whose type is `sip.simplewrapper`. It is an extension of the `PyObject` structure and so may be safely cast to it.

  void *`data`

    This is initialised to the address of the C/C++ instance. If an access function is subsequently provided then it may be used for any purpose by the access function.

  sipAccessFunc `access_func`

    This is the address of an optional access function that is called, with a pointer to this structure as its first argument. If its second argument is `UnguardedPointer` then it returns the address of the C/C++ instance, even if it is known that its value is no longer valid. If the second argument is `GuardedPointer` then it returns the address of the C++ instance or `0` if it is known to be invalid. If the second argument is `ReleaseGuard` then the structure is being deallocated and any dynamic resources used by the access function should be released. If there is no access function then the `sipSimpleWrapper.data` is used as the address of the C/C++ instance. Typically a custom meta-type is used to set an access method after the Python object has been created.

  PyObject *`user`

    This can be used for any purpose by handwritten code and will automatically be garbage collected at the appropriate time.

PyTypeObject *`sipSimpleWrapper_Type`

  This is the type of a `sipSimpleWrapper` structure and is the C implementation of `sip.simplewrapper`. It may be safely cast to `sipWrapperType`.

`sipStringTypeClassMap`

  Deprecated since version 4.8.

  This C structure is used with `sipMapStringToClass()` to define a mapping between `'\0'` terminated string based RTTI and Generated Type Objects. The structure elements are as follows.

  char *`typeString`

    The `'\0'` terminated string RTTI.

  sipWrapperType **`pyType.`

    A pointer to the corresponding generated type object.

void `sipTransferBack`(PyObject *obj)

  This transfers ownership of a Python wrapped instance to Python (see Ownership of Objects).

  Parameters: | obj – the wrapped instance.

  In addition, any association of the instance with regard to the cyclic garbage collector with another instance is removed.

void `sipTransferBreak`(PyObject *obj)

  Any association of a Python wrapped instance with regard to the cyclic garbage collector with another instance is removed. Ownership of the instance should be with C++.

  Parameters: | obj – the wrapped instance.

void `sipTransferTo`(PyObject *obj, PyObject *owner)

  This transfers ownership of a Python wrapped instance to C++ (see Ownership of Objects).

  Parameters: | obj – the wrapped instance. owner – an optional wrapped instance that obj becomes associated with with regard to the cyclic garbage collector. If owner is `NULL` then no such association is made. If owner is the same value as obj then any reference cycles involving obj can never be detected or broken by the cyclic garbage collector. Responsibility for calling the C++ instance’s destructor is always transfered to C++.

PyTypeObject *`sipTypeAsPyTypeObject`(sipTypeDef *td)

  This returns a pointer to the Python type object that SIP creates for a generated type structure.

  Parameters: | td – the type structure.
  Returns: | the Python type object. If the type structure refers to a mapped type then `NULL` will be returned.

  If the type structure refers to a C structure or C++ class then the Python type object may be safely cast to a `sipWrapperType`.

const sipTypeDef *`sipTypeFromPyTypeObject`(PyTypeObject *py_type)

  This returns the generated type structure for a Python type object.

  Parameters: | py_type – the Python type object.
  Returns: | the type structure or `NULL` if the Python type object doesn’t correspond to a type structure.

int `sipTypeIsClass`(sipTypeDef *td)

  This checks if a generated type structure refers to a C structure or C++ class.

  Parameters: | td – the type structure.
  Returns: | a non-zero value if the type structure refers to a structure or class.

int `sipTypeIsEnum`(sipTypeDef *td)

  This checks if a generated type structure refers to a named enum.

  Parameters: | td – the type structure.
  Returns: | a non-zero value if the type structure refers to an enum.

int `sipTypeIsMapped`(sipTypeDef *td)

  This checks if a generated type structure refers to a mapped type.

  Parameters: | td – the type structure.
  Returns: | a non-zero value if the type structure refers to a mapped type.

int `sipTypeIsNamespace`(sipTypeDef *td)

  This checks if a generated type structure refers to a C++ namespace.

  Parameters: | td – the type structure.
  Returns: | a non-zero value if the type structure refers to a namespace.

const char *`sipTypeName`(const sipTypeDef *td)

  This returns the C/C++ name of a wrapped type.

  Parameters: | td – the type’s generated type structure.
  Returns: | the name of the C/C++ type.

const sipTypeDef *`sipTypeScope`(const sipTypeDef *td)

  This returns the generated type structure of the enclosing scope of another generated type structure.

  Parameters: | td – the type structure.
  Returns: | the type structure of the scope or `NULL` if the type has no scope.

PyTypeObject *`sipVoidPtr_Type`

  This is the type of a `PyObject` structure that is used to wrap a `void *`.

`sipWrapper`

  This is a C structure that represents a Python wrapped instance whose type is `sip.wrapper`. It is an extension of the `sipSimpleWrapper` and `PyObject` structures and so may be safely cast to both.

int `sipWrapper_Check`(PyObject *obj)

  Deprecated since version 4.8: Use the following instead:

  > PyObject_TypeCheck(obj, sipWrapper_Type)

  This checks if a Python object is a wrapped instance.

  Parameters: | obj – the Python object.
  Returns: | a non-zero value if the Python object is a wrapped instance.

PyTypeObject *`sipWrapper_Type`

  This is the type of a `sipWrapper` structure and is the C implementation of `sip.wrapper`. It may be safely cast to `sipWrapperType`.

`sipWrapperType`

  This is a C structure that represents a SIP generated type object. It is an extension of the `PyTypeObject` structure (which is itself an extension of the `PyObject` structure) and so may be safely cast to `PyTypeObject` (and `PyObject`).

PyTypeObject *`sipWrapperType_Type`

  This is the type of a `sipWrapperType` structure and is the C implementation of `sip.wrappertype`.

## Generated Type Structures

SIP generates an opaque type structure for each C structure, C++ class, C++ namespace, named enum or mapped type being wrapped. These are `sipTypeDef` structures and are used extensively by the SIP API.

The names of these structure are prefixed by `sipType_`.

For those structures that correspond to C structures, C++ classes, C++ namespaces or named enums the remaining part of the name is the fully qualified name of the structure, class, namespace or enum name. Any `::` scope separators are replaced by an underscore. For example, the type object for class `Klass` is `sipType_Klass`.

For those structure that correspond to mapped types the remaining part of the name is generated by SIP. The only way for handwritten code to obtain a pointer to a structure for a mapped type is to use `sipFindType()`.

The type structures of all imported types are available to handwritten code.

## Generated Type Objects

Deprecated since version 4.8: Use the corresponding generated type structure (see Generated Type Structures) and `sipTypeAsPyTypeObject()` instead.

SIP generates a `sipWrapperType` type object for each C structure or C++ class being wrapped.

These objects are named with the structure or class name prefixed by `sipClass_`. For example, the type object for class `Klass` is `sipClass_Klass`.

## Generated Named Enum Type Objects

Deprecated since version 4.8: Use the corresponding generated type structure (see Generated Type Structures) and `sipTypeAsPyTypeObject()` instead.

SIP generates a type object for each named enum being wrapped. These are PyTypeObject structures. (Anonymous enums are wrapped as Python integers.)

These objects are named with the fully qualified enum name (i.e. including any enclosing scope) prefixed by `sipEnum_`. For example, the type object for enum `Enum` defined in class `Klass` is `sipEnum_Klass_Enum`.

## Generated Derived Classes

For most C++ classes being wrapped SIP generates a derived class with the same name prefixed by `sip`. For example, the derived class for class `Klass` is `sipKlass`.

If a C++ class doesn’t have any virtual or protected methods in it or any of it’s super-class hierarchy, or does not emit any Qt signals, then a derived class is not generated.

Most of the time handwritten code should ignore the derived classes. The only exception is that handwritten constructor code specified using the `%MethodCode` directive should call the derived class’s constructor (which has the same C++ signature) rather then the wrapped class’s constructor.

## Generated Exception Objects

SIP generates a Python object for each exception defined with the `%Exception` directive.

These objects are named with the fully qualified exception name (i.e. including any enclosing scope) prefixed by `sipException_`. For example, the type object for enum `Except` defined in class `Klass` is `sipException_Klass_Except`.

The objects of all imported exceptions are available to handwritten code.

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