Directives — SIP 4.10.5 Reference Guide

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# Directives

In this section we describe each of the directives that can be used in specification files. All directives begin with `%` as the first non-whitespace character in a line.

Some directives have arguments or contain blocks of code or documentation. In the following descriptions these are shown in italics. Optional arguments are enclosed in [brackets].

Some directives are used to specify handwritten code. Handwritten code must not define names that start with the prefix `sip`.

`%AccessCode`

    %AccessCode
        code
    %End

This directive is used immediately after the declaration of an instance of a wrapped class or structure, or a pointer to such an instance. You use it to provide handwritten code that overrides the default behaviour.

For example:

    class Klass;

    Klass *klassInstance;
    %AccessCode
        // In this contrived example the C++ library we are wrapping defines
        // klassInstance as Klass ** (which SIP doesn't support) so we
        // explicitly dereference it.
        if (klassInstance && *klassInstance)
            return *klassInstance;

        // This will get converted to None.
        return 0;
    %End

`%API`

New in version 4.9.

    %API name version

This directive is used to define an API and set its default version number. A version number must be greater than or equal to 1.

See Managing Incompatible APIs for more detail.

For example:

    %API PyTQt4 1

`%BIGetBufferCode`

    %BIGetBufferCode
        code
    %End

This directive (along with `%BIReleaseBufferCode`) is used to specify code that implements the buffer interface of Python v3. If Python v2 is being used then this is ignored.

The following variables are made available to the handwritten code:

Py_buffer *sipBuffer
  This is a pointer to the Python buffer structure that the handwritten code must populate.
type *sipCpp
  This is a pointer to the structure or class instance. Its type is a pointer to the structure or class.
int sipFlags
  These are the flags that specify what elements of the `sipBuffer` structure must be populated.
int sipRes
  The handwritten code should set this to 0 if there was no error or -1 if there was an error.
PyObject *sipSelf
  This is the Python object that wraps the structure or class instance, i.e. `self`.

`%BIGetCharBufferCode`

    %BIGetCharBufferCode
        code
    %End

This directive (along with `%BIGetReadBufferCode`, `%BIGetSegCountCode` and `%BIGetWriteBufferCode`) is used to specify code that implements the buffer interface of Python v2. If Python v3 is being used then this is ignored.

The following variables are made available to the handwritten code:

type *sipCpp
  This is a pointer to the structure or class instance. Its type is a pointer to the structure or class.
void **sipPtrPtr
  This is the pointer used to return the address of the character buffer.
`SIP_SSIZE_T` sipRes
  The handwritten code should set this to the length of the character buffer or -1 if there was an error.
`SIP_SSIZE_T` sipSegment
  This is the number of the segment of the character buffer.
PyObject *sipSelf
  This is the Python object that wraps the structure or class instance, i.e. `self`.

`%BIGetReadBufferCode`

    %BIGetReadBufferCode
        code
    %End

This directive (along with `%BIGetCharBufferCode`, `%BIGetSegCountCode` and `%BIGetWriteBufferCode`) is used to specify code that implements the buffer interface of Python v2. If Python v3 is being used then this is ignored.

The following variables are made available to the handwritten code:

type *sipCpp
  This is a pointer to the structure or class instance. Its type is a pointer to the structure or class.
void **sipPtrPtr
  This is the pointer used to return the address of the read buffer.
`SIP_SSIZE_T` sipRes
  The handwritten code should set this to the length of the read buffer or -1 if there was an error.
`SIP_SSIZE_T` sipSegment
  This is the number of the segment of the read buffer.
PyObject *sipSelf
  This is the Python object that wraps the structure or class instance, i.e. `self`.

`%BIGetSegCountCode`

    %BIGetSegCountCode
        code
    %End

This directive (along with `%BIGetCharBufferCode`, `%BIGetReadBufferCode` and `%BIGetWriteBufferCode`) is used to specify code that implements the buffer interface of Python v2. If Python v3 is being used then this is ignored.

The following variables are made available to the handwritten code:

type *sipCpp
  This is a pointer to the structure or class instance. Its type is a pointer to the structure or class.
`SIP_SSIZE_T` *sipLenPtr
  This is the pointer used to return the total length in bytes of all segments of the buffer.
`SIP_SSIZE_T` sipRes
  The handwritten code should set this to the number of segments that make up the buffer.
PyObject *sipSelf
  This is the Python object that wraps the structure or class instance, i.e. `self`.

`%BIGetWriteBufferCode`

    %BIGetWriteBufferCode
        code
    %End

This directive (along with `%BIGetCharBufferCode`, `%BIGetReadBufferCode` and `%BIGetSegCountCode` is used to specify code that implements the buffer interface of Python v2. If Python v3 is being used then this is ignored.

The following variables are made available to the handwritten code:

type *sipCpp
  This is a pointer to the structure or class instance. Its type is a pointer to the structure or class.
void **sipPtrPtr
  This is the pointer used to return the address of the write buffer.
`SIP_SSIZE_T` sipRes
  The handwritten code should set this to the length of the write buffer or -1 if there was an error.
`SIP_SSIZE_T` sipSegment
  This is the number of the segment of the write buffer.
PyObject *sipSelf
  This is the Python object that wraps the structure or class instance, i.e. `self`.

`%BIReleaseBufferCode`

    %BIReleaseBufferCode
        code
    %End

This directive (along with `%BIGetBufferCode`) is used to specify code that implements the buffer interface of Python v3. If Python v2 is being used then this is ignored.

The following variables are made available to the handwritten code:

Py_buffer *sipBuffer
  This is a pointer to the Python buffer structure.
type *sipCpp
  This is a pointer to the structure or class instance. Its type is a pointer to the structure or class.
PyObject *sipSelf
  This is the Python object that wraps the structure or class instance, i.e. `self`.

`%CModule`

    %CModule name [version]

This directive is used to identify that the library being wrapped is a C library and to define the name of the module and it’s optional version number.

See the `%Module` directive for an explanation of the version number.

For example:

    %CModule dbus 1

`%CompositeModule`

    %CompositeModule name

A composite module is one that merges a number of related SIP generated modules. For example, a module that merges the modules `a_mod`, `b_mod` and `c_mod` is equivalent to the following pure Python module:

    from a_mod import *
    from b_mod import *
    from c_mod import *

Clearly the individual modules should not define module-level objects with the same name.

This directive is used to specify the name of a composite module. Any subsequent `%CModule` or `%Module` directive is interpreted as defining a component module.

For example:

    %CompositeModule PyTQt4.TQt
    %Include TQtCore/TQtCoremod.sip
    %Include TQtGui/TQtGuimod.sip

The main purpose of a composite module is as a programmer convenience as they don’t have to remember which which individual module an object is defined in.

`%ConsolidatedModule`

    %ConsolidatedModule name

A consolidated module is one that consolidates the wrapper code of a number of SIP generated modules (refered to as component modules in this context).

This directive is used to specify the name of a consolidated module. Any subsequent `%CModule` or `%Module` directive is interpreted as defining a component module.

For example:

    %ConsolidatedModule PyTQt4._qt
    %Include TQtCore/TQtCoremod.sip
    %Include TQtGui/TQtGuimod.sip

A consolidated module is not intended to be explicitly imported by an application. Instead it is imported by its component modules when they themselves are imported.

Normally the wrapper code is contained in the component module and is linked against the corresponding C or C++ library. The advantage of a consolidated module is that it allows all of the wrapped C or C++ libraries to be linked against a single module. If the linking is done statically then deployment of generated modules can be greatly simplified.

It follows that a component module can be built in one of two ways, as a normal standalone module, or as a component of a consolidated module. When building as a component the `-p` command line option should be used to specify the name of the consolidated module.

`%ConvertFromTypeCode`

    %ConvertFromTypeCode
        code
    %End

This directive is used as part of the `%MappedType` directive to specify the handwritten code that converts an instance of a mapped type to a Python object.

The following variables are made available to the handwritten code:

type *sipCpp
  This is a pointer to the instance of the mapped type to be converted. It will never be zero as the conversion from zero to `Py_None` is handled before the handwritten code is called.
PyObject *sipTransferObj
  This specifies any desired ownership changes to the returned object. If it is `NULL` then the ownership should be left unchanged. If it is `Py_None` then ownership should be transferred to Python. Otherwise ownership should be transferred to C/C++ and the returned object associated with sipTransferObj. The code can choose to interpret these changes in any way. For example, if the code is converting a C++ container of wrapped classes to a Python list it is likely that the ownership changes should be made to each element of the list.

The handwritten code must explicitly return a `PyObject *`. If there was an error then a Python exception must be raised and `NULL` returned.

The following example converts a `TQPtrList<TQWidget *>` instance to a Python list of `TQWidget` instances:

    %ConvertFromTypeCode
        PyObject *l;

        // Create the Python list of the correct length.
        if ((l = PyList_New(sipCpp->size())) == NULL)
            return NULL;

        // Go through each element in the C++ instance and convert it to a
        // wrapped TQWidget.
        for (int i = 0; i < sipCpp->size(); ++i)
        {
            TQWidget *w = sipCpp->at(i);
            PyObject *wobj;

            // Get the Python wrapper for the TQWidget instance, creating a new
            // one if necessary, and handle any ownership transfer.
            if ((wobj = sipConvertFromType(w, sipType_TQWidget, sipTransferObj)) == NULL)
            {
                // There was an error so garbage collect the Python list.
                Py_DECREF(l);
                return NULL;
            }

            // Add the wrapper to the list.
            PyList_SetItem(l, i, wobj);
        }

        // Return the Python list.
        return l;
    %End

`%ConvertToSubClassCode`

    %ConvertToSubClassCode
        code
    %End

When SIP needs to wrap a C++ class instance it first checks to make sure it hasn’t already done so. If it has then it just returns a new reference to the corresponding Python object. Otherwise it creates a new Python object of the appropriate type. In C++ a function may be defined to return an instance of a certain class, but can often return a sub-class instead.

This directive is used to specify handwritten code that exploits any available real-time type information (RTTI) to see if there is a more specific Python type that can be used when wrapping the C++ instance. The RTTI may be provided by the compiler or by the C++ instance itself.

The directive is included in the specification of one of the classes that the handwritten code handles the type conversion for. It doesn’t matter which one, but a sensible choice would be the one at the root of that class hierarchy in the module.

Note that if a class hierarchy extends over a number of modules then this directive should be used in each of those modules to handle the part of the hierarchy defined in that module. SIP will ensure that the different pieces of code are called in the right order to determine the most specific Python type to use.

The following variables are made available to the handwritten code:

type *sipCpp
  This is a pointer to the C++ class instance.
void **sipCppRet
  When the sub-class is derived from more than one super-class then it is possible that the C++ address of the instance as the sub-class is different to that of the super-class. If so, then this must be set to the C++ address of the instance when cast (usually using `static_cast`) from the super-class to the sub-class.
const sipTypeDef *sipType
  The handwritten code must set this to the SIP generated type structure that corresponds to the class instance. (The type structure for class `Klass` is `sipType_Klass`.) If the RTTI of the class instance isn’t recognised then `sipType` must be set to `NULL`. The code doesn’t have to recognise the exact class, only the most specific sub-class that it can.
sipWrapperType *sipClass

  The handwritten code must set this to the SIP generated Python type object that corresponds to the class instance. (The type object for class `Klass` is `sipClass_Klass`.) If the RTTI of the class instance isn’t recognised then `sipClass` must be set to `NULL`. The code doesn’t have to recognise the exact class, only the most specific sub-class that it can.

  This is deprecated from SIP v4.8. Instead you should use `sipType`.

The handwritten code must not explicitly return.

The following example shows the sub-class conversion code for `TQEvent` based class hierarchy in PyTQt:

    class TQEvent
    {
    %ConvertToSubClassCode
        // TQEvent sub-classes provide a unique type ID.
        switch (sipCpp->type())
        {
        case TQEvent::Timer:
            sipType = sipType_TQTimerEvent;
            break;

        case TQEvent::KeyPress:
        case TQEvent::KeyRelease:
            sipType = sipType_TQKeyEvent;
            break;

        // Skip the remaining event types to keep the example short.

        default:
            // We don't recognise the type.
            sipType = NULL;
        }
    %End

        // The rest of the class specification.

    };

`%ConvertToTypeCode`

    %ConvertToTypeCode
        code
    %End

This directive is used to specify the handwritten code that converts a Python object to a mapped type instance and to handle any ownership transfers. It is used as part of the `%MappedType` directive and as part of a class specification. The code is also called to determine if the Python object is of the correct type prior to conversion.

When used as part of a class specification it can automatically convert additional types of Python object. For example, PyTQt uses it in the specification of the `TQString` class to allow Python string objects and unicode objects to be used wherever `TQString` instances are expected.

The following variables are made available to the handwritten code:

int *sipIsErr
  If this is `NULL` then the code is being asked to check the type of the Python object. The check must not have any side effects. Otherwise the code is being asked to convert the Python object and a non-zero value should be returned through this pointer if an error occurred during the conversion.
PyObject *sipPy
  This is the Python object to be converted.
type **sipCppPtr
  This is a pointer through which the address of the mapped type instance (or zero if appropriate) is returned. Its value is undefined if `sipIsErr` is `NULL`.
PyObject *sipTransferObj
  This specifies any desired ownership changes to sipPy. If it is `NULL` then the ownership should be left unchanged. If it is `Py_None` then ownership should be transferred to Python. Otherwise ownership should be transferred to C/C++ and sipPy associated with sipTransferObj. The code can choose to interpret these changes in any way.

The handwritten code must explicitly return an `int` the meaning of which depends on the value of `sipIsErr`.

If `sipIsErr` is `NULL` then a non-zero value is returned if the Python object has a type that can be converted to the mapped type. Otherwise zero is returned.

If `sipIsErr` is not `NULL` then a combination of the following flags is returned.

> - `SIP_TEMPORARY` is set to indicate that the returned instance is a temporary and should be released to avoid a memory leak.
> - `SIP_DERIVED_CLASS` is set to indicate that the type of the returned instance is a derived class. See Generated Derived Classes.

The following example converts a Python list of `TQPoint` instances to a `TQPtrList<TQPoint>` instance:

    %ConvertToTypeCode
        // See if we are just being asked to check the type of the Python
        // object.
        if (!sipIsErr)
        {
            // Checking whether or not None has been passed instead of a list
            // has already been done.
            if (!PyList_Check(sipPy))
                return 0;

            // Check the type of each element.  We specify SIP_NOT_NONE to
            // disallow None because it is a list of TQPoint, not of a pointer
            // to a TQPoint, so None isn't appropriate.
            for (int i = 0; i < PyList_GET_SIZE(sipPy); ++i)
                if (!sipCanConvertToType(PyList_GET_ITEM(sipPy, i),
                                         sipType_TQPoint, SIP_NOT_NONE))
                    return 0;

            // The type is valid.
            return 1;
        }

        // Create the instance on the heap.
        TQPtrList<TQPoint> *ql = new TQPtrList<TQPoint>;

        for (int i = 0; i < PyList_GET_SIZE(sipPy); ++i)
        {
            TQPoint *qp;
            int state;

            // Get the address of the element's C++ instance.  Note that, in
            // this case, we don't apply any ownership changes to the list
            // elements, only to the list itself.
            qp = reinterpret_cast<TQPoint *>(sipConvertToType(
                                                    PyList_GET_ITEM(sipPy, i),
                                                    sipType_TQPoint, 0,
                                                    SIP_NOT_NONE,
                                                    &state, sipIsErr));

            // Deal with any errors.
            if (*sipIsErr)
            {
                sipReleaseType(qp, sipType_TQPoint, state);

                // Tidy up.
                delete ql;

                // There is no temporary instance.
                return 0;
            }

            ql->append(*qp);

            // A copy of the TQPoint was appended to the list so we no longer
            // need it.  It may be a temporary instance that should be
            // destroyed, or a wrapped instance that should not be destroyed.
            // sipReleaseType() will do the right thing.
            sipReleaseType(qp, sipType_TQPoint, state);
        }

        // Return the instance.
        *sipCppPtr = ql;

        // The instance should be regarded as temporary (and be destroyed as
        // soon as it has been used) unless it has been transferred from
        // Python.  sipGetState() is a convenience function that implements
        // this common transfer behaviour.
        return sipGetState(sipTransferObj);
    %End

When used in a class specification the handwritten code replaces the code that would normally be automatically generated. This means that the handwritten code must also handle instances of the class itself and not just the additional types that are being supported. This should be done by making calls to `sipCanConvertToType()` to check the object type and `sipConvertToType()` to convert the object. The `SIP_NO_CONVERTORS` flag must be passed to both these functions to prevent recursive calls to the handwritten code.

`%Copying`

    %Copying
        text
    %End

This directive is used to specify some arbitrary text that will be included at the start of all source files generated by SIP. It is normally used to include copyright and licensing terms.

For example:

    %Copying
    Copyright (c) 2009 Riverbank Computing Limited
    %End

`%DefaultEncoding`

    %DefaultEncoding string

This directive is used to specify the default encoding used for `char`, `const char`, `char *` or `const char *` values. The encoding can be either `"ASCII"`, `"Latin-1"`, `"UTF-8"` or `"None"`. An encoding of `"None"` means that the value is unencoded. The default can be overridden for a particular value using the `Encoding` annotation. If the directive is not specified then `"None"` is used.

For example:

    %DefaultEncoding "Latin-1"

`%DefaultMetatype`

    %DefaultMetatype dotted-name

This directive is used to specify the Python type that should be used as the meta-type for any C/C++ data type defined in the same module, and by importing modules, that doesn’t have an explicit meta-type.

If this is not specified then `sip.wrappertype` is used.

You can also use the `Metatype` class annotation to specify the meta-type used by a particular C/C++ type.

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

For example:

    %DefaultMetatype PyTQt4.TQtCore.pytqtWrapperType

`%DefaultSupertype`

    %DefaultSupertype dotted-name

This directive is used to specify the Python type that should be used as the super-type for any C/C++ data type defined in the same module that doesn’t have an explicit super-type.

If this is not specified then `sip.wrapper` is used.

You can also use the `Supertype` class annotation to specify the super-type used by a particular C/C++ type.

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

For example:

    %DefaultSupertype sip.simplewrapper

`%Doc`

    %Doc
        text
    %End

This directive is used to specify some arbitrary text that will be extracted by SIP when the `-d` command line option is used. The directive can be specified any number of times and SIP will concatenate all the separate pieces of text in the order that it sees them.

Documentation that is specified using this directive is local to the module in which it appears. It is ignored by modules that `%Import` it. Use the `%ExportedDoc` directive for documentation that should be included by all modules that `%Import` this one.

For example:

    %Doc
    <h1>An Example</h1>
    <p>
    This fragment of documentation is HTML and is local to the module in
    which it is defined.
    </p>
    %End

`%Docstring`

    %Docstring
        text
    %End

New in version 4.10.

This directive is used to specify explicit docstrings for classes, functions and methods.

The docstring of a class is made up of the docstring specified for the class itself, with the docstrings specified for each contructor appended.

The docstring of a function or method is made up of the concatenated docstrings specified for each of the overloads.

Specifying an explicit docstring will prevent SIP from generating an automatic docstring that describes the Python signature of a function or method overload. This means that SIP will generate less informative exceptions (i.e. without a full signature) when it fails to match a set of arguments to any function or method overload.

For example:

    class Klass
    {
    %Docstring
    This will be at the start of the class's docstring.
    %End

    public:
        Klass();
    %Docstring
    This will be appended to the class's docstring.
    %End
    };

`%End`

This isn’t a directive in itself, but is used to terminate a number of directives that allow a block of handwritten code or text to be specified.

`%Exception`

    %Exception name [(base-exception)]
    {
        [*header-code]
        raise-code
    };

This directive is used to define new Python exceptions, or to provide a stub for existing Python exceptions. It allows handwritten code to be provided that implements the translation between C++ exceptions and Python exceptions. The arguments to `throw ()` specifiers must either be names of classes or the names of Python exceptions defined by this directive.

name is the name of the exception.

base-exception is the optional base exception. This may be either one of the standard Python exceptions or one defined with a previous `%Exception` directive.

header-code is the optional `%TypeHeaderCode` used to specify any external interface to the exception being defined.

raise-code is the `%RaiseCode` used to specify the handwritten code that converts a reference to the C++ exception to the Python exception.

For example:

    %Exception std::exception(SIP_Exception) /PyName=StdException/
    {
    %TypeHeaderCode
    #include <exception>
    %End
    %RaiseCode
            const char *detail = sipExceptionRef.what();

            SIP_BLOCK_THREADS
            PyErr_SetString(sipException_std_exception, detail);
            SIP_UNBLOCK_THREADS
    %End
    };

In this example we map the standard C++ exception to a new Python exception. The new exception is called `StdException` and is derived from the standard Python exception `Exception`.

An exception may be annotated with `Default` to specify that it should be caught by default if there is no `throw` clause.

`%ExportedDoc`

    %ExportedDoc
        text
    %End

This directive is used to specify some arbitrary text that will be extracted by SIP when the `-d` command line option is used. The directive can be specified any number of times and SIP will concatenate all the separate pieces of text in the order that it sees them.

Documentation that is specified using this directive will also be included by modules that `%Import` it.

For example:

    %ExportedDoc
    ==========
    An Example
    ==========

    This fragment of documentation is reStructuredText and will appear in the
    module in which it is defined and all modules that %Import it.
    %End

`%ExportedHeaderCode`

    %ExportedHeaderCode
        code
    %End

This directive is used to specify handwritten code, typically the declarations of types, that is placed in a header file that is included by all generated code for all modules. It should not include function declarations because Python modules should not explicitly call functions in another Python module.

See also `%ModuleCode` and `%ModuleHeaderCode`.

`%Feature`

    %Feature name

This directive is used to declare a feature. Features (along with `%Platforms` and `%Timeline`) are used by the `%If` directive to control whether or not parts of a specification are processed or ignored.

Features are mutually independent of each other - any combination of features may be enabled or disable. By default all features are enabled. The SIP `-x` command line option is used to disable a feature.

If a feature is enabled then SIP will automatically generate a corresponding C preprocessor symbol for use by handwritten code. The symbol is the name of the feature prefixed by `SIP_FEATURE_`.

For example:

    %Feature FOO_SUPPORT

    %If (FOO_SUPPORT)
    void foo();
    %End

`%GCClearCode`

    %GCClearCode
        code
    %End

Python has a cyclic garbage collector which can identify and release unneeded objects even when their reference counts are not zero. If a wrapped C structure or C++ class keeps its own reference to a Python object then, if the garbage collector is to do its job, it needs to provide some handwritten code to traverse and potentially clear those embedded references.

See the section Supporting cyclic garbage collection in Embedding and Extending the Python Interpreter for the details.

This directive is used to specify the code that clears any embedded references. (See `%GCTraverseCode` for specifying the code that traverses any embedded references.)

The following variables are made available to the handwritten code:

type *sipCpp
  This is a pointer to the structure or class instance. Its type is a pointer to the structure or class.
int sipRes
  The handwritten code should set this to the result to be returned.

The following simplified example is taken from PyTQt. The `TQCustomEvent` class allows arbitary data to be attached to the event. In PyTQt this data is always a Python object and so should be handled by the garbage collector:

    %GCClearCode
        PyObject *obj;

        // Get the object.
        obj = reinterpret_cast<PyObject *>(sipCpp->data());

        // Clear the pointer.
        sipCpp->setData(0);

        // Clear the reference.
        Py_XDECREF(obj);

        // Report no error.
        sipRes = 0;
    %End

`%GCTraverseCode`

    %GCTraverseCode
        code
    %End

This directive is used to specify the code that traverses any embedded references for Python’s cyclic garbage collector. (See `%GCClearCode` for a full explanation.)

The following variables are made available to the handwritten code:

type *sipCpp
  This is a pointer to the structure or class instance. Its type is a pointer to the structure or class.
visitproc sipVisit
  This is the visit function provided by the garbage collector.
void *sipArg
  This is the argument to the visit function provided by the garbage collector.
int sipRes
  The handwritten code should set this to the result to be returned.

The following simplified example is taken from PyTQt’s `TQCustomEvent` class:

    %GCTraverseCode
        PyObject *obj;

        // Get the object.
        obj = reinterpret_cast<PyObject *>(sipCpp->data());

        // Call the visit function if there was an object.
        if (obj)
            sipRes = sipVisit(obj, sipArg);
        else
            sipRes = 0;
    %End

`%GetCode`

    %GetCode
        code
    %End

This directive is used after the declaration of a C++ class variable or C structure member to specify handwritten code to convert it to a Python object. It is usually used to handle types that SIP cannot deal with automatically.

The following variables are made available to the handwritten code:

type *sipCpp
  This is a pointer to the structure or class instance. Its type is a pointer to the structure or class. It is not made available if the variable being wrapped is a static class variable.
PyObject *sipPy
  The handwritten code must set this to the Python representation of the class variable or structure member. If there is an error then the code must raise an exception and set this to `NULL`.
PyObject *sipPyType
  If the variable being wrapped is a static class variable then this is the Python type object of the class from which the variable was referenced (not the class in which it is defined). It may be safely cast to a PyTypeObject * or a sipWrapperType *.

For example:

    struct Entity
    {
        /*
         * In this contrived example the C library we are wrapping actually
         * defines this as char buffer[100] which SIP cannot handle
         * automatically.
         */
        char *buffer;
    %GetCode
            sipPy = PyString_FromStringAndSize(sipCpp->buffer, 100);
    %End
    %SetCode
            char *ptr;
            int length;

            if (PyString_AsStringAndSize(sipPy, &ptr, &length) == -1)
                sipErr = 1;
            else if (length != 100)
            {
                /*
                 * Raise an exception because the length isn't exactly right.
                 */

                PyErr_SetString(PyExc_ValueError, "an Entity.buffer must be exactly 100 bytes");
                sipErr = 1;
            }
            else
                memcpy(sipCpp->buffer, ptr, 100);
    %End
    }

`%If`

    %If (expression)
        specification
    %End

where

    expression ::= [ored-qualifiers | range]

    ored-qualifiers ::= [qualifier | qualifier || ored-qualifiers]

    qualifier ::= [!] [feature | platform]

    range ::= [version] - [version]

This directive is used in conjunction with features (see `%Feature`), platforms (see `%Platforms`) and versions (see `%Timeline`) to control whether or not parts of a specification are processed or not.

A range of versions means all versions starting with the lower bound up to but excluding the upper bound. If the lower bound is omitted then it is interpreted as being before the earliest version. If the upper bound is omitted then it is interpreted as being after the latest version.

For example:

    %Feature SUPPORT_FOO
    %Platforms {WIN32_PLATFORM POSIX_PLATFORM MACOS_PLATFORM}
    %Timeline {V1_0 V1_1 V2_0 V3_0}

    %If (!SUPPORT_FOO)
        // Process this if the SUPPORT_FOO feature is disabled.
    %End

    %If (POSIX_PLATFORM || MACOS_PLATFORM)
        // Process this if either the POSIX_PLATFORM or MACOS_PLATFORM
        // platforms are enabled.
    %End

    %If (V1_0 - V2_0)
        // Process this if either V1_0 or V1_1 is enabled.
    %End

    %If (V2_0 - )
        // Process this if either V2_0 or V3_0 is enabled.
    %End

    %If ( - )
        // Always process this.
    %End

Note that this directive is not implemented as a preprocessor. Only the following parts of a specification are affected by it:

> - `%API`
> - `class`
> - `%ConvertFromTypeCode`
> - `%ConvertToSubClassCode`
> - `%ConvertToTypeCode`
> - `enum`
> - `%DefaultEncoding`
> - `%DefaultMetatype`
> - `%DefaultSupertype`
> - `%ExportedHeaderCode`
> - functions
> - `%GCClearCode`
> - `%GCTraverseCode`
> - `%If`
> - `%InitialisationCode`
> - `%MappedType`
> - `%MethodCode`
> - `%ModuleCode`
> - `%ModuleHeaderCode`
> - `namespace`
> - `%PostInitialisationCode`
> - `%PreInitialisationCode`
> - `struct`
> - `typedef`
> - `%TypeCode`
> - `%TypeHeaderCode`
> - `%UnitCode`
> - variables
> - `%VirtualCatcherCode`

Also note that the only way to specify the logical and of qualifiers is to use nested `%If` directives.

`%Import`

    %Import filename

This directive is used to import the specification of another module. This is needed if the current module makes use of any types defined in the imported module, e.g. as an argument to a function, or to sub-class.

If filename cannot be opened then SIP prepends filename with the name of the directory containing the current specification file (i.e. the one containing the `%Import` directive) and tries again. If this also fails then SIP prepends filename with each of the directories, in turn, specified by the `-I` command line option.

For example:

    %Import tqt/tqtmod.sip

`%Include`

    %Include filename

This directive is used to include contents of another file as part of the specification of the current module. It is the equivalent of the C preprocessor’s `#include` directive and is used to structure a large module specification into manageable pieces.

`%Include` follows the same search process as `%Import` when trying to open filename.

For example:

    %Include qwidget.sip

`%InitialisationCode`

    %InitialisationCode
        code
    %End

This directive is used to specify handwritten code that is embedded in-line in the generated module initialisation code after the SIP module has been imported but before the module itself has been initialised.

It is typically used to call `sipRegisterPyType()`.

For example:

    %InitialisationCode
        // The code will be executed when the module is first imported, after
        // the SIP module has been imported, but before other module-specific
        // initialisation has been completed.
    %End

`%License`

    %License /license-annotations/

This directive is used to specify the contents of an optional license dictionary. The license dictionary is called `__license__` and is stored in the module dictionary. The elements of the dictionary are specified using the `Licensee`, `Signature`, `Timestamp` and `Type` annotations. Only the `Type` annotation is compulsory.

Note that this directive isn’t an attempt to impose any licensing restrictions on a module. It is simply a method for easily embedding licensing information in a module so that it is accessible to Python scripts.

For example:

    %License /Type="GPL"/

`%MappedType`

    template<type-list>
    %MappedType type
    {
        [header-code]
        [convert-to-code]
        [convert-from-code]
    };

    %MappedType type
    {
        [header-code]
        [convert-to-code]
        [convert-from-code]
    };

This directive is used to define an automatic mapping between a C or C++ type and a Python type. It can be used as part of a template, or to map a specific type.

When used as part of a template type cannot itself refer to a template. Any occurrences of any of the type names (but not any `*` or `&`) in type-list will be replaced by the actual type names used when the template is instantiated. Template mapped types are instantiated automatically as required (unlike template classes which are only instantiated using `typedef`).

Any explicit mapped type will be used in preference to any template that maps the same type, ie. a template will not be automatically instantiated if there is an explicit mapped type.

header-code is the `%TypeHeaderCode` used to specify the library interface to the type being mapped.

convert-to-code is the `%ConvertToTypeCode` used to specify the handwritten code that converts a Python object to an instance of the mapped type.

convert-from-code is the `%ConvertFromTypeCode` used to specify the handwritten code that converts an instance of the mapped type to a Python object.

For example:

    template<Type *>
    %MappedType TQPtrList
    {
    %TypeHeaderCode
    // Include the library interface to the type being mapped.
    #include <qptrlist.h>
    %End

    %ConvertToTypeCode
        // See if we are just being asked to check the type of the Python
        // object.
        if (sipIsErr == NULL)
        {
            // Check it is a list.
            if (!PyList_Check(sipPy))
                return 0;

            // Now check each element of the list is of the type we expect.
            // The template is for a pointer type so we don't disallow None.
            for (int i = 0; i < PyList_GET_SIZE(sipPy); ++i)
                if (!sipCanConvertToType(PyList_GET_ITEM(sipPy, i),
                                         sipType_Type, 0))
                    return 0;

            return 1;
        }

        // Create the instance on the heap.
        TQPtrList<Type *> *ql = new TQPtrList<Type *>;

        for (int i = 0; i < PyList_GET_SIZE(sipPy); ++i)
        {
            // Use the SIP API to convert the Python object to the
            // corresponding C++ instance.  Note that we apply any ownership
            // transfer to the list itself, not the individual elements.
            Type *t = reinterpret_cast<Type *>(sipConvertToType(
                                                PyList_GET_ITEM(sipPy, i),
                                                sipType_Type, 0, 0, 0,
                                                sipIsErr));

            if (*sipIsErr)
            {
                // Tidy up.
                delete ql;

                // There is nothing on the heap.
                return 0;
            }

            // Add the pointer to the C++ instance.
            ql->append(t);
        }

        // Return the instance on the heap.
        *sipCppPtr = ql;

        // Apply the normal transfer.
        return sipGetState(sipTransferObj);
    %End

    %ConvertFromTypeCode
        PyObject *l;

        // Create the Python list of the correct length.
        if ((l = PyList_New(sipCpp->size())) == NULL)
            return NULL;

        // Go through each element in the C++ instance and convert it to the
        // corresponding Python object.
        for (int i = 0; i < sipCpp->size(); ++i)
        {
            Type *t = sipCpp->at(i);
            PyObject *tobj;

            if ((tobj = sipConvertFromType(t, sipType_Type, sipTransferObj)) == NULL)
            {
                // There was an error so garbage collect the Python list.
                Py_DECREF(l);
                return NULL;
            }

            PyList_SetItem(l, i, tobj);
        }

        // Return the Python list.
        return l;
    %End
    }

Using this we can use, for example, `TQPtrList<TQObject *>` throughout the module’s specification files (and in any module that imports this one). The generated code will automatically map this to and from a Python list of TQObject instances when appropriate.

`%MethodCode`

    %MethodCode
        code
    %End

This directive is used as part of the specification of a global function, class method, operator, constructor or destructor to specify handwritten code that replaces the normally generated call to the function being wrapped. It is usually used to handle argument types and results that SIP cannot deal with automatically.

Normally the specified code is embedded in-line after the function’s arguments have been successfully converted from Python objects to their C or C++ equivalents. In this case the specified code must not include any `return` statements.

However if the `NoArgParser` annotation has been used then the specified code is also responsible for parsing the arguments. No other code is generated by SIP and the specified code must include a `return` statement.

In the context of a destructor the specified code is embedded in-line in the Python type’s deallocation function. Unlike other contexts it supplements rather than replaces the normally generated code, so it must not include code to return the C structure or C++ class instance to the heap. The code is only called if ownership of the structure or class is with Python.

The specified code must also handle the Python Global Interpreter Lock (GIL). If compatibility with SIP v3.x is required then the GIL must be released immediately before the C++ call and reacquired immediately afterwards as shown in this example fragment:

    Py_BEGIN_ALLOW_THREADS
    sipCpp->foo();
    Py_END_ALLOW_THREADS

If compatibility with SIP v3.x is not required then this is optional but should be done if the C++ function might block the current thread or take a significant amount of time to execute. (See The Python Global Interpreter Lock and the `ReleaseGIL` and `HoldGIL` annotations.)

If the `NoArgParser` annotation has not been used then the following variables are made available to the handwritten code:

type a0

  There is a variable for each argument of the Python signature (excluding any `self` argument) named `a0`, `a1`, etc. The type of the variable is the same as the type defined in the specification with the following exceptions:

  - if the argument is only used to return a value (e.g. it is an `int *` without an `In` annotation) then the type has one less level of indirection (e.g. it will be an `int`)
  - if the argument is a structure or class (or a reference or a pointer to a structure or class) then type will always be a pointer to the structure or class.

  Note that handwritten code for destructors never has any arguments.

PyObject *a0Wrapper
  This variable is made available only if the `GetWrapper` annotation is specified for the corresponding argument. The variable is a pointer to the Python object that wraps the argument.
type *sipCpp

  If the directive is used in the context of a class constructor then this must be set by the handwritten code to the constructed instance. If it is set to `0` and no Python exception is raised then SIP will continue to try other Python signatures.

  If the directive is used in the context of a method (but not the standard binary operator methods, e.g. `__add__()`) or a destructor then this is a pointer to the C structure or C++ class instance.

  Its type is a pointer to the structure or class.

  Standard binary operator methods follow the same convention as global functions and instead define two arguments called `a0` and `a1`.

sipErrorState sipError

  The handwritten code should set this to either `sipErrorContinue` or `sipErrorFail`, and raise an appropriate Python exception, if an error is detected. Its initial value will be `sipErrorNone`.

  When `sipErrorContinue` is used, SIP will remember the exception as the reason why the particular overloaded callable could not be invoked. It will then continue to try the next overloaded callable. It is typically used by code that needs to do additional type checking of the callable’s arguments.

  When `sipErrorFail1` is used, SIP will report the exception immediately and will not attempt to invoke other overloaded callables.

  `sipError` is not provided for destructors.

int sipIsErr

  The handwritten code should set this to a non-zero value, and raise an appropriate Python exception, if an error is detected. This is the equivalent of setting `sipError` to `sipErrorFail`. Its initial value will be `0`.

  `sipIsErr` is not provided for destructors.

type sipRes

  The handwritten code should set this to the result to be returned. The type of the variable is the same as the type defined in the Python signature in the specification with the following exception:

  - if the argument is a structure or class (or a reference or a pointer to a structure or class) then type will always be a pointer to the structure or class.

  `sipRes` is not provided for inplace operators (e.g. `+=` or `__imul__()`) as their results are handled automatically, nor for class constructors or destructors.

PyObject *sipSelf
  If the directive is used in the context of a class constructor, destructor or method then this is the Python object that wraps the structure or class instance, i.e. `self`.
bool sipSelfWasArg

  This is only made available for non-abstract, virtual methods. It is set if `self` was explicitly passed as the first argument of the method rather than being bound to the method. In other words, the call was:

      Klass.foo(self, ...)

  rather than:

      self.foo(...)

If the `NoArgParser` annotation has been used then only the following variables are made available to the handwritten code:

PyObject *sipArgs
  This is the tuple of arguments.
PyObject *sipKwds
  This is the dictionary of keyword arguments.

The following is a complete example:

    class Klass
    {
    public:
        virtual int foo(SIP_PYTUPLE);
    %MethodCode
            // The C++ API takes a 2 element array of integers but passing a
            // two element tuple is more Pythonic.

            int iarr[2];

            if (PyArg_ParseTuple(a0, "ii", &iarr[0], &iarr[1]))
            {
                Py_BEGIN_ALLOW_THREADS
                sipRes = sipSelfWasArg ? sipCpp->Klass::foo(iarr)
                                       : sipCpp->foo(iarr);
                Py_END_ALLOW_THREADS
            }
            else
            {
                // PyArg_ParseTuple() will have raised the exception.
                sipIsErr = 1;
            }
    %End
    };

As the example is a virtual method [1], note the use of `sipSelfWasArg` to determine exactly which implementation of `foo()` to call.

If a method is in the `protected` section of a C++ class then SIP generates helpers that provide access to method. However, these are not available if the Python module is being built with `protected` redefined as `public`.

The following pattern should be used to cover all possibilities:

    #if defined(SIP_PROTECTED_IS_PUBLIC)
        sipRes = sipSelfWasArg ? sipCpp->Klass::foo(iarr)
                               : sipCpp->foo(iarr);
    #else
        sipRes = sipCpp->sipProtectVirt_foo(sipSelfWasArg, iarr);
    #endif

If a method is in the `protected` section of a C++ class but is not virtual then the pattern should instead be:

    #if defined(SIP_PROTECTED_IS_PUBLIC)
        sipRes = sipCpp->foo(iarr);
    #else
        sipRes = sipCpp->sipProtect_foo(iarr);
    #endif

[1] | See `%VirtualCatcherCode` for a description of how SIP generated code handles the reimplementation of C++ virtual methods in Python.

`%Module`

    %Module name [version]

This directive is used to identify that the library being wrapped is a C++ library and to define the name of the module and it’s optional version number.

The name may contain periods to specify that the module is part of a Python package.

The optional version number is useful if you (or others) might create other modules that build on this module, i.e. if another module might `%Import` this module. Under the covers, a module exports an API that is used by modules that `%Import` it and the API is given a version number. A module built on that module knows the version number of the API that it is expecting. If, when the modules are imported at run-time, the version numbers do not match then a Python exception is raised. The dependent module must then be re-built using the correct specification files for the base module.

The version number should be incremented whenever a module is changed. Some changes don’t affect the exported API, but it is good practice to change the version number anyway.

For example:

    %Module tqt 5

`%ModuleCode`

    %ModuleCode
        code
    %End

This directive is used to specify handwritten code, typically the implementations of utility functions, that can be called by other handwritten code in the module.

For example:

    %ModuleCode
    // Print an object on stderr for debugging purposes.
    void dump_object(PyObject *o)
    {
        PyObject_Print(o, stderr, 0);
        fprintf(stderr, "\n");
    }
    %End

See also `%ExportedHeaderCode` and `%ModuleHeaderCode`.

`%ModuleHeaderCode`

    %ModuleHeaderCode
        code
    %End

This directive is used to specify handwritten code, typically the declarations of utility functions, that is placed in a header file that is included by all generated code for the same module.

For example:

    %ModuleHeaderCode
    void dump_object(PyObject *o);
    %End

See also `%ExportedHeaderCode` and `%ModuleCode`.

`%OptionalInclude`

    %OptionalInclude filename

This directive is identical to the `%Include` directive except that SIP silently continues processing if filename could not be opened.

For example:

    %OptionalInclude license.sip

`%PickleCode`

    %PickleCode
        code
    %End

This directive is used to specify handwritten code to pickle a C structure or C++ class instance.

The following variables are made available to the handwritten code:

type *sipCpp
  This is a pointer to the structure or class instance. Its type is a pointer to the structure or class.
PyObject *sipRes
  The handwritten code must set this to a tuple of the arguments that will be passed to the type’s __init__() method when the structure or class instance is unpickled. If there is an error then the code must raise an exception and set this to `NULL`.

For example:

    class Point
    {
        Point(int x, y);

        int x() const;
        int y() const;

    %PickleCode
        sipRes = Py_BuildValue("ii", sipCpp->x(), sipCpp->y());
    %End
    }

Note that SIP works around the Python limitation that prevents nested types being pickled.

Both named and unnamed enums can be pickled automatically without providing any handwritten code.

`%Platforms`

    %Platforms {name name ...}

This directive is used to declare a set of platforms. Platforms (along with `%Feature` and `%Timeline`) are used by the `%If` directive to control whether or not parts of a specification are processed or ignored.

Platforms are mutually exclusive - only one platform can be enabled at a time. By default all platforms are disabled. The SIP `-t` command line option is used to enable a platform.

For example:

    %Platforms {WIN32_PLATFORM POSIX_PLATFORM MACOS_PLATFORM}

    %If (WIN32_PLATFORM)
    void undocumented();
    %End

    %If (POSIX_PLATFORM)
    void documented();
    %End

`%PostInitialisationCode`

    %PostInitialisationCode
        code
    %End

This directive is used to specify handwritten code that is embedded in-line at the very end of the generated module initialisation code.

The following variables are made available to the handwritten code:

PyObject *sipModule
  This is the module object returned by `Py_InitModule()`.
PyObject *sipModuleDict
  This is the module’s dictionary object returned by `Py_ModuleGetDict()`.

For example:

    %PostInitialisationCode
        // The code will be executed when the module is first imported and
        // after all other initialisation has been completed.
    %End

`%PreInitialisationCode`

    %PreInitialisationCode
        code
    %End

This directive is used to specify handwritten code that is embedded in-line at the very start of the generated module initialisation code.

For example:

    %PreInitialisationCode
        // The code will be executed when the module is first imported and
        // before other initialisation has been completed.
    %End

`%RaiseCode`

    %RaiseCode
        code
    %End

This directive is used as part of the definition of an exception using the `%Exception` directive to specify handwritten code that raises a Python exception when a C++ exception has been caught. The code is embedded in-line as the body of a C++ `catch ()` clause.

The specified code must handle the Python Global Interpreter Lock (GIL) if necessary. The GIL must be acquired before any calls to the Python API and released after the last call as shown in this example fragment:

    SIP_BLOCK_THREADS
    PyErr_SetNone(PyErr_Exception);
    SIP_UNBLOCK_THREADS

Finally, the specified code must not include any `return` statements.

The following variable is made available to the handwritten code:

type &sipExceptionRef
  This is a reference to the caught C++ exception. The type of the reference is the same as the type defined in the `throw ()` specifier.

See the `%Exception` directive for an example.

`%SetCode`

    %SetCode
        code
    %End

This directive is used after the declaration of a C++ class variable or C structure member to specify handwritten code to convert it from a Python object. It is usually used to handle types that SIP cannot deal with automatically.

The following variables are made available to the handwritten code:

type *sipCpp
  This is a pointer to the structure or class instance. Its type is a pointer to the structure or class. It is not made available if the variable being wrapped is a static class variable.
int sipErr
  If the conversion failed then the handwritten code should raise a Python exception and set this to a non-zero value. Its initial value will be automatically set to zero.
PyObject *sipPy
  This is the Python object that the handwritten code should convert.
PyObject *sipPyType
  If the variable being wrapped is a static class variable then this is the Python type object of the class from which the variable was referenced (not the class in which it is defined). It may be safely cast to a PyTypeObject * or a sipWrapperType *.

See the `%GetCode` directive for an example.

`%Timeline`

    %Timeline {name name ...}

This directive is used to declare a set of versions released over a period of time. Versions (along with `%Feature` and `%Platforms`) are used by the `%If` directive to control whether or not parts of a specification are processed or ignored.

Versions are mutually exclusive - only one version can be enabled at a time. By default all versions are disabled. The SIP `-t` command line option is used to enable a version.

For example:

    %Timeline {V1_0 V1_1 V2_0 V3_0}

    %If (V1_0 - V2_0)
    void foo();
    %End

    %If (V2_0 -)
    void foo(int = 0);
    %End

`%Timeline` can be used any number of times in a module to allow multiple libraries to be wrapped in the same module.

`%TypeCode`

    %TypeCode
        code
    %End

This directive is used as part of the specification of a C structure or a C++ class to specify handwritten code, typically the implementations of utility functions, that can be called by other handwritten code in the structure or class.

For example:

    class Klass
    {
    %TypeCode
    // Print an instance on stderr for debugging purposes.
    static void dump_klass(const Klass *k)
    {
        fprintf(stderr,"Klass %s at %p\n", k->name(), k);
    }
    %End

        // The rest of the class specification.

    };

Because the scope of the code is normally within the generated file that implements the type, any utility functions would normally be declared `static`. However a naming convention should still be adopted to prevent clashes of function names within a module in case the SIP `-j` command line option is used.

`%TypeHeaderCode`

    %TypeHeaderCode
        code
    %End

This directive is used to specify handwritten code that defines the interface to a C or C++ type being wrapped, either a structure, a class, or a template. It is used within a class definition or a `%MappedType` directive.

Normally code will be a pre-processor `#include` statement.

For example:

    // Wrap the Klass class.
    class Klass
    {
    %TypeHeaderCode
    #include <klass.h>
    %End

        // The rest of the class specification.
    };

`%UnitCode`

    %UnitCode
        code
    %End

This directive is used to specify handwritten code that it included at the very start of a generated compilation unit (ie. C or C++ source file). It is typically used to `#include` a C++ precompiled header file.

`%VirtualCatcherCode`

    %VirtualCatcherCode
        code
    %End

For most classes there are corresponding generated derived classes that contain reimplementations of the class’s virtual methods. These methods (which SIP calls catchers) determine if there is a corresponding Python reimplementation and call it if so. If there is no Python reimplementation then the method in the original class is called instead.

This directive is used to specify handwritten code that replaces the normally generated call to the Python reimplementation and the handling of any returned results. It is usually used to handle argument types and results that SIP cannot deal with automatically.

This directive can also be used in the context of a class destructor to specify handwritten code that is embedded in-line in the internal derived class’s destructor.

In the context of a method the Python Global Interpreter Lock (GIL) is automatically acquired before the specified code is executed and automatically released afterwards.

In the context of a destructor the specified code must handle the GIL. The GIL must be acquired before any calls to the Python API and released after the last call as shown in this example fragment:

    SIP_BLOCK_THREADS
    Py_DECREF(obj);
    SIP_UNBLOCK_THREADS

The following variables are made available to the handwritten code in the context of a method:

type a0
  There is a variable for each argument of the C++ signature named `a0`, `a1`, etc. The type of the variable is the same as the type defined in the specification.
int a0Key
  There is a variable for each argument of the C++ signature that has a type where it is important to ensure that the corresponding Python object is not garbage collected too soon. This only applies to output arguments that return `'\0'` terminated strings. The variable would normally be passed to `sipParseResult()` using either the `A` or `B` format characters.
int sipIsErr
  The handwritten code should set this to a non-zero value, and raise an appropriate Python exception, if an error is detected.
PyObject *sipMethod
  This object is the Python reimplementation of the virtual C++ method. It is normally passed to `sipCallMethod()`.
type sipRes
  The handwritten code should set this to the result to be returned. The type of the variable is the same as the type defined in the C++ signature in the specification.
int sipResKey
  This variable is only made available if the result has a type where it is important to ensure that the corresponding Python object is not garbage collected too soon. This only applies to `'\0'` terminated strings. The variable would normally be passed to `sipParseResult()` using either the `A` or `B` format characters.
sipSimpleWrapper *sipPySelf
  This variable is only made available if either the `a0Key` or `sipResKey` are made available. It defines the context within which keys are unique. The variable would normally be passed to `sipParseResult()` using the `S` format character.

No variables are made available in the context of a destructor.

For example:

    class Klass
    {
    public:
        virtual int foo(SIP_PYTUPLE) [int (int *)];
    %MethodCode
            // The C++ API takes a 2 element array of integers but passing a
            // two element tuple is more Pythonic.

            int iarr[2];

            if (PyArg_ParseTuple(a0, "ii", &iarr[0], &iarr[1]))
            {
                Py_BEGIN_ALLOW_THREADS
                sipRes = sipCpp->Klass::foo(iarr);
                Py_END_ALLOW_THREADS
            }
            else
            {
                // PyArg_ParseTuple() will have raised the exception.
                sipIsErr = 1;
            }
    %End
    %VirtualCatcherCode
            // Convert the 2 element array of integers to the two element
            // tuple.

            PyObject *result;

            result = sipCallMethod(&sipIsErr, sipMethod, "ii", a0[0], a0[1]);

            if (result != NULL)
            {
                // Convert the result to the C++ type.
                sipParseResult(&sipIsErr, sipMethod, result, "i", &sipRes);

                Py_DECREF(result);
            }
    %End
    };

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