/*
pybind11/pytypes.h: Convenience wrapper classes for basic Python types
Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>
All rights reserved. Use of this source code is governed by a
BSD-style license that can be found in the LICENSE file.
*/
#pragma once
#include "detail/common.h"
#include "buffer_info.h"
#include <utility>
#include <type_traits>
NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
/* A few forward declarations */
class handle; class object;
class str; class iterator;
struct arg; struct arg_v;
NAMESPACE_BEGIN(detail)
class args_proxy;
inline bool isinstance_generic(handle obj, const std::type_info &tp);
// Accessor forward declarations
template <typename Policy> class accessor;
namespace accessor_policies {
struct obj_attr;
struct str_attr;
struct generic_item;
struct sequence_item;
struct list_item;
struct tuple_item;
}
using obj_attr_accessor = accessor<accessor_policies::obj_attr>;
using str_attr_accessor = accessor<accessor_policies::str_attr>;
using item_accessor = accessor<accessor_policies::generic_item>;
using sequence_accessor = accessor<accessor_policies::sequence_item>;
using list_accessor = accessor<accessor_policies::list_item>;
using tuple_accessor = accessor<accessor_policies::tuple_item>;
/// Tag and check to identify a class which implements the Python object API
class pyobject_tag { };
template <typename T> using is_pyobject = std::is_base_of<pyobject_tag, remove_reference_t<T>>;
/** \rst
A mixin class which adds common functions to `handle`, `object` and various accessors.
The only requirement for `Derived` is to implement ``PyObject *Derived::ptr() const``.
\endrst */
template <typename Derived>
class object_api : public pyobject_tag {
const Derived &derived() const { return static_cast<const Derived &>(*this); }
public:
/** \rst
Return an iterator equivalent to calling ``iter()`` in Python. The object
must be a collection which supports the iteration protocol.
\endrst */
iterator begin() const;
/// Return a sentinel which ends iteration.
iterator end() const;
/** \rst
Return an internal functor to invoke the object's sequence protocol. Casting
the returned ``detail::item_accessor`` instance to a `handle` or `object`
subclass causes a corresponding call to ``__getitem__``. Assigning a `handle`
or `object` subclass causes a call to ``__setitem__``.
\endrst */
item_accessor operator[](handle key) const;
/// See above (the only difference is that they key is provided as a string literal)
item_accessor operator[](const char *key) const;
/** \rst
Return an internal functor to access the object's attributes. Casting the
returned ``detail::obj_attr_accessor`` instance to a `handle` or `object`
subclass causes a corresponding call to ``getattr``. Assigning a `handle`
or `object` subclass causes a call to ``setattr``.
\endrst */
obj_attr_accessor attr(handle key) const;
/// See above (the only difference is that they key is provided as a string literal)
str_attr_accessor attr(const char *key) const;
/** \rst
Matches * unpacking in Python, e.g. to unpack arguments out of a ``tuple``
or ``list`` for a function call. Applying another * to the result yields
** unpacking, e.g. to unpack a dict as function keyword arguments.
See :ref:`calling_python_functions`.
\endrst */
args_proxy operator*() const;
/// Check if the given item is contained within this object, i.e. ``item in obj``.
template <typename T> bool contains(T &&item) const;
/** \rst
Assuming the Python object is a function or implements the ``__call__``
protocol, ``operator()`` invokes the underlying function, passing an
arbitrary set of parameters. The result is returned as a `object` and
may need to be converted back into a Python object using `handle::cast()`.
When some of the arguments cannot be converted to Python objects, the
function will throw a `cast_error` exception. When the Python function
call fails, a `error_already_set` exception is thrown.
\endrst */
template <return_value_policy policy = return_value_policy::automatic_reference, typename... Args>
object operator()(Args &&...args) const;
template <return_value_policy policy = return_value_policy::automatic_reference, typename... Args>
PYBIND11_DEPRECATED("call(...) was deprecated in favor of operator()(...)")
object call(Args&&... args) const;
/// Equivalent to ``obj is other`` in Python.
bool is(object_api const& other) const { return derived().ptr() == other.derived().ptr(); }
/// Equivalent to ``obj is None`` in Python.
bool is_none() const { return derived().ptr() == Py_None; }
PYBIND11_DEPRECATED("Use py::str(obj) instead")
pybind11::str str() const;
/// Get or set the object's docstring, i.e. ``obj.__doc__``.
str_attr_accessor doc() const;
/// Return the object's current reference count
int ref_count() const { return static_cast<int>(Py_REFCNT(derived().ptr())); }
/// Return a handle to the Python type object underlying the instance
handle get_type() const;
};
NAMESPACE_END(detail)
/** \rst
Holds a reference to a Python object (no reference counting)
The `handle` class is a thin wrapper around an arbitrary Python object (i.e. a
``PyObject *`` in Python's C API). It does not perform any automatic reference
counting and merely provides a basic C++ interface to various Python API functions.
.. seealso::
The `object` class inherits from `handle` and adds automatic reference
counting features.
\endrst */
class handle : public detail::object_api<handle> {
public:
/// The default constructor creates a handle with a ``nullptr``-valued pointer
handle() = default;
/// Creates a ``handle`` from the given raw Python object pointer
handle(PyObject *ptr) : m_ptr(ptr) { } // Allow implicit conversion from PyObject*
/// Return the underlying ``PyObject *`` pointer
PyObject *ptr() const { return m_ptr; }
PyObject *&ptr() { return m_ptr; }
/** \rst
Manually increase the reference count of the Python object. Usually, it is
preferable to use the `object` class which derives from `handle` and calls
this function automatically. Returns a reference to itself.
\endrst */
const handle& inc_ref() const & { Py_XINCREF(m_ptr); return *this; }
/** \rst
Manually decrease the reference count of the Python object. Usually, it is
preferable to use the `object` class which derives from `handle` and calls
this function automatically. Returns a reference to itself.
\endrst */
const handle& dec_ref() const & { Py_XDECREF(m_ptr); return *this; }
/** \rst
Attempt to cast the Python object into the given C++ type. A `cast_error`
will be throw upon failure.
\endrst */
template <typename T> T cast() const;
/// Return ``true`` when the `handle` wraps a valid Python object
explicit operator bool() const { return m_ptr != nullptr; }
/** \rst
Deprecated: Check that the underlying pointers are the same.
Equivalent to ``obj1 is obj2`` in Python.
\endrst */
PYBIND11_DEPRECATED("Use obj1.is(obj2) instead")
bool operator==(const handle &h) const { return m_ptr == h.m_ptr; }
PYBIND11_DEPRECATED("Use !obj1.is(obj2) instead")
bool operator!=(const handle &h) const { return m_ptr != h.m_ptr; }
PYBIND11_DEPRECATED("Use handle::operator bool() instead")
bool check() const { return m_ptr != nullptr; }
protected:
PyObject *m_ptr = nullptr;
};
/** \rst
Holds a reference to a Python object (with reference counting)
Like `handle`, the `object` class is a thin wrapper around an arbitrary Python
object (i.e. a ``PyObject *`` in Python's C API). In contrast to `handle`, it
optionally increases the object's reference count upon construction, and it
*always* decreases the reference count when the `object` instance goes out of
scope and is destructed. When using `object` instances consistently, it is much
easier to get reference counting right at the first attempt.
\endrst */
class object : public handle {
public:
object() = default;
PYBIND11_DEPRECATED("Use reinterpret_borrow<object>() or reinterpret_steal<object>()")
object(handle h, bool is_borrowed) : handle(h) { if (is_borrowed) inc_ref(); }
/// Copy constructor; always increases the reference count
object(const object &o) : handle(o) { inc_ref(); }
/// Move constructor; steals the object from ``other`` and preserves its reference count
object(object &&other) noexcept { m_ptr = other.m_ptr; other.m_ptr = nullptr; }
/// Destructor; automatically calls `handle::dec_ref()`
~object() { dec_ref(); }
/** \rst
Resets the internal pointer to ``nullptr`` without without decreasing the
object's reference count. The function returns a raw handle to the original
Python object.
\endrst */
handle release() {
PyObject *tmp = m_ptr;
m_ptr = nullptr;
return handle(tmp);
}
object& operator=(const object &other) {
other.inc_ref();
dec_ref();
m_ptr = other.m_ptr;
return *this;
}
object& operator=(object &&other) noexcept {
if (this != &other) {
handle temp(m_ptr);
m_ptr = other.m_ptr;
other.m_ptr = nullptr;
temp.dec_ref();
}
return *this;
}
// Calling cast() on an object lvalue just copies (via handle::cast)
template <typename T> T cast() const &;
// Calling on an object rvalue does a move, if needed and/or possible
template <typename T> T cast() &&;
protected:
// Tags for choosing constructors from raw PyObject *
struct borrowed_t { };
struct stolen_t { };
template <typename T> friend T reinterpret_borrow(handle);
template <typename T> friend T reinterpret_steal(handle);
public:
// Only accessible from derived classes and the reinterpret_* functions
object(handle h, borrowed_t) : handle(h) { inc_ref(); }
object(handle h, stolen_t) : handle(h) { }
};
/** \rst
Declare that a `handle` or ``PyObject *`` is a certain type and borrow the reference.
The target type ``T`` must be `object` or one of its derived classes. The function
doesn't do any conversions or checks. It's up to the user to make sure that the
target type is correct.
.. code-block:: cpp
PyObject *p = PyList_GetItem(obj, index);
py::object o = reinterpret_borrow<py::object>(p);
// or
py::tuple t = reinterpret_borrow<py::tuple>(p); // <-- `p` must be already be a `tuple`
\endrst */
template <typename T> T reinterpret_borrow(handle h) { return {h, object::borrowed_t{}}; }
/** \rst
Like `reinterpret_borrow`, but steals the reference.
.. code-block:: cpp
PyObject *p = PyObject_Str(obj);
py::str s = reinterpret_steal<py::str>(p); // <-- `p` must be already be a `str`
\endrst */
template <typename T> T reinterpret_steal(handle h) { return {h, object::stolen_t{}}; }
NAMESPACE_BEGIN(detail)
inline std::string error_string();
NAMESPACE_END(detail)
/// Fetch and hold an error which was already set in Python. An instance of this is typically
/// thrown to propagate python-side errors back through C++ which can either be caught manually or
/// else falls back to the function dispatcher (which then raises the captured error back to
/// python).
class error_already_set : public std::runtime_error {
public:
/// Constructs a new exception from the current Python error indicator, if any. The current
/// Python error indicator will be cleared.
error_already_set() : std::runtime_error(detail::error_string()) {
PyErr_Fetch(&type.ptr(), &value.ptr(), &trace.ptr());
}
inline ~error_already_set();
/// Give the currently-held error back to Python, if any. If there is currently a Python error
/// already set it is cleared first. After this call, the current object no longer stores the
/// error variables (but the `.what()` string is still available).
void restore() { PyErr_Restore(type.release().ptr(), value.release().ptr(), trace.release().ptr()); }
// Does nothing; provided for backwards compatibility.
PYBIND11_DEPRECATED("Use of error_already_set.clear() is deprecated")
void clear() {}
/// Check if the currently trapped error type matches the given Python exception class (or a
/// subclass thereof). May also be passed a tuple to search for any exception class matches in
/// the given tuple.
bool matches(handle ex) const { return PyErr_GivenExceptionMatches(ex.ptr(), type.ptr()); }
private:
object type, value, trace;
};
/** \defgroup python_builtins _
Unless stated otherwise, the following C++ functions behave the same
as their Python counterparts.
*/
/** \ingroup python_builtins
\rst
Return true if ``obj`` is an instance of ``T``. Type ``T`` must be a subclass of
`object` or a class which was exposed to Python as ``py::class_<T>``.
\endrst */
template <typename T, detail::enable_if_t<std::is_base_of<object, T>::value, int> = 0>
bool isinstance(handle obj) { return T::check_(obj); }
template <typename T, detail::enable_if_t<!std::is_base_of<object, T>::value, int> = 0>
bool isinstance(handle obj) { return detail::isinstance_generic(obj, typeid(T)); }
template <> inline bool isinstance<handle>(handle obj) = delete;
template <> inline bool isinstance<object>(handle obj) { return obj.ptr() != nullptr; }
/// \ingroup python_builtins
/// Return true if ``obj`` is an instance of the ``type``.
inline bool isinstance(handle obj, handle type) {
const auto result = PyObject_IsInstance(obj.ptr(), type.ptr());
if (result == -1)
throw error_already_set();
return result != 0;
}
/// \addtogroup python_builtins
/// @{
inline bool hasattr(handle obj, handle name) {
return PyObject_HasAttr(obj.ptr(), name.ptr()) == 1;
}
inline bool hasattr(handle obj, const char *name) {
return PyObject_HasAttrString(obj.ptr(), name) == 1;
}
inline object getattr(handle obj, handle name) {
PyObject *result = PyObject_GetAttr(obj.ptr(), name.ptr());
if (!result) { throw error_already_set(); }
return reinterpret_steal<object>(result);
}
inline object getattr(handle obj, const char *name) {
PyObject *result = PyObject_GetAttrString(obj.ptr(), name);
if (!result) { throw error_already_set(); }
return reinterpret_steal<object>(result);
}
inline object getattr(handle obj, handle name, handle default_) {
if (PyObject *result = PyObject_GetAttr(obj.ptr(), name.ptr())) {
return reinterpret_steal<object>(result);
} else {
PyErr_Clear();
return reinterpret_borrow<object>(default_);
}
}
inline object getattr(handle obj, const char *name, handle default_) {
if (PyObject *result = PyObject_GetAttrString(obj.ptr(), name)) {
return reinterpret_steal<object>(result);
} else {
PyErr_Clear();
return reinterpret_borrow<object>(default_);
}
}
inline void setattr(handle obj, handle name, handle value) {
if (PyObject_SetAttr(obj.ptr(), name.ptr(), value.ptr()) != 0) { throw error_already_set(); }
}
inline void setattr(handle obj, const char *name, handle value) {
if (PyObject_SetAttrString(obj.ptr(), name, value.ptr()) != 0) { throw error_already_set(); }
}
inline ssize_t hash(handle obj) {
auto h = PyObject_Hash(obj.ptr());
if (h == -1) { throw error_already_set(); }
return h;
}
/// @} python_builtins
NAMESPACE_BEGIN(detail)
inline handle get_function(handle value) {
if (value) {
#if PY_MAJOR_VERSION >= 3
if (PyInstanceMethod_Check(value.ptr()))
value = PyInstanceMethod_GET_FUNCTION(value.ptr());
else
#endif
if (PyMethod_Check(value.ptr()))
value = PyMethod_GET_FUNCTION(value.ptr());
}
return value;
}
// Helper aliases/functions to support implicit casting of values given to python accessors/methods.
// When given a pyobject, this simply returns the pyobject as-is; for other C++ type, the value goes
// through pybind11::cast(obj) to convert it to an `object`.
template <typename T, enable_if_t<is_pyobject<T>::value, int> = 0>
auto object_or_cast(T &&o) -> decltype(std::forward<T>(o)) { return std::forward<T>(o); }
// The following casting version is implemented in cast.h:
template <typename T, enable_if_t<!is_pyobject<T>::value, int> = 0>
object object_or_cast(T &&o);
// Match a PyObject*, which we want to convert directly to handle via its converting constructor
inline handle object_or_cast(PyObject *ptr) { return ptr; }
template <typename Policy>
class accessor : public object_api<accessor<Policy>> {
using key_type = typename Policy::key_type;
public:
accessor(handle obj, key_type key) : obj(obj), key(std::move(key)) { }
accessor(const accessor &) = default;
accessor(accessor &&) = default;
// accessor overload required to override default assignment operator (templates are not allowed
// to replace default compiler-generated assignments).
void operator=(const accessor &a) && { std::move(*this).operator=(handle(a)); }
void operator=(const accessor &a) & { operator=(handle(a)); }
template <typename T> void operator=(T &&value) && {
Policy::set(obj, key, object_or_cast(std::forward<T>(value)));
}
template <typename T> void operator=(T &&value) & {
get_cache() = reinterpret_borrow<object>(object_or_cast(std::forward<T>(value)));
}
template <typename T = Policy>
PYBIND11_DEPRECATED("Use of obj.attr(...) as bool is deprecated in favor of pybind11::hasattr(obj, ...)")
explicit operator enable_if_t<std::is_same<T, accessor_policies::str_attr>::value ||
std::is_same<T, accessor_policies::obj_attr>::value, bool>() const {
return hasattr(obj, key);
}
template <typename T = Policy>
PYBIND11_DEPRECATED("Use of obj[key] as bool is deprecated in favor of obj.contains(key)")
explicit operator enable_if_t<std::is_same<T, accessor_policies::generic_item>::value, bool>() const {
return obj.contains(key);
}
operator object() const { return get_cache(); }
PyObject *ptr() const { return get_cache().ptr(); }
template <typename T> T cast() const { return get_cache().template cast<T>(); }
private:
object &get_cache() const {
if (!cache) { cache = Policy::get(obj, key); }
return cache;
}
private:
handle obj;
key_type key;
mutable object cache;
};
NAMESPACE_BEGIN(accessor_policies)
struct obj_attr {
using key_type = object;
static object get(handle obj, handle key) { return getattr(obj, key); }
static void set(handle obj, handle key, handle val) { setattr(obj, key, val); }
};
struct str_attr {
using key_type = const char *;
static object get(handle obj, const char *key) { return getattr(obj, key); }
static void set(handle obj, const char *key, handle val) { setattr(obj, key, val); }
};
struct generic_item {
using key_type = object;
static object get(handle obj, handle key) {
PyObject *result = PyObject_GetItem(obj.ptr(), key.ptr());
if (!result) { throw error_already_set(); }
return reinterpret_steal<object>(result);
}
static void set(handle obj, handle key, handle val) {
if (PyObject_SetItem(obj.ptr(), key.ptr(), val.ptr()) != 0) { throw error_already_set(); }
}
};
struct sequence_item {
using key_type = size_t;
static object get(handle obj, size_t index) {
PyObject *result = PySequence_GetItem(obj.ptr(), static_cast<ssize_t>(index));
if (!result) { throw error_already_set(); }
return reinterpret_steal<object>(result);
}
static void set(handle obj, size_t index, handle val) {
// PySequence_SetItem does not steal a reference to 'val'
if (PySequence_SetItem(obj.ptr(), static_cast<ssize_t>(index), val.ptr()) != 0) {
throw error_already_set();
}
}
};
struct list_item {
using key_type = size_t;
static object get(handle obj, size_t index) {
PyObject *result = PyList_GetItem(obj.ptr(), static_cast<ssize_t>(index));
if (!result) { throw error_already_set(); }
return reinterpret_borrow<object>(result);
}
static void set(handle obj, size_t index, handle val) {
// PyList_SetItem steals a reference to 'val'
if (PyList_SetItem(obj.ptr(), static_cast<ssize_t>(index), val.inc_ref().ptr()) != 0) {
throw error_already_set();
}
}
};
struct tuple_item {
using key_type = size_t;
static object get(handle obj, size_t index) {
PyObject *result = PyTuple_GetItem(obj.ptr(), static_cast<ssize_t>(index));
if (!result) { throw error_already_set(); }
return reinterpret_borrow<object>(result);
}
static void set(handle obj, size_t index, handle val) {
// PyTuple_SetItem steals a reference to 'val'
if (PyTuple_SetItem(obj.ptr(), static_cast<ssize_t>(index), val.inc_ref().ptr()) != 0) {
throw error_already_set();
}
}
};
NAMESPACE_END(accessor_policies)
/// STL iterator template used for tuple, list, sequence and dict
template <typename Policy>
class generic_iterator : public Policy {
using It = generic_iterator;
public:
using difference_type = ssize_t;
using iterator_category = typename Policy::iterator_category;
using value_type = typename Policy::value_type;
using reference = typename Policy::reference;
using pointer = typename Policy::pointer;
generic_iterator() = default;
generic_iterator(handle seq, ssize_t index) : Policy(seq, index) { }
reference operator*() const { return Policy::dereference(); }
reference operator[](difference_type n) const { return *(*this + n); }
pointer operator->() const { return **this; }
It &operator++() { Policy::increment(); return *this; }
It operator++(int) { auto copy = *this; Policy::increment(); return copy; }
It &operator--() { Policy::decrement(); return *this; }
It operator--(int) { auto copy = *this; Policy::decrement(); return copy; }
It &operator+=(difference_type n) { Policy::advance(n); return *this; }
It &operator-=(difference_type n) { Policy::advance(-n); return *this; }
friend It operator+(const It &a, difference_type n) { auto copy = a; return copy += n; }
friend It operator+(difference_type n, const It &b) { return b + n; }
friend It operator-(const It &a, difference_type n) { auto copy = a; return copy -= n; }
friend difference_type operator-(const It &a, const It &b) { return a.distance_to(b); }
friend bool operator==(const It &a, const It &b) { return a.equal(b); }
friend bool operator!=(const It &a, const It &b) { return !(a == b); }
friend bool operator< (const It &a, const It &b) { return b - a > 0; }
friend bool operator> (const It &a, const It &b) { return b < a; }
friend bool operator>=(const It &a, const It &b) { return !(a < b); }
friend bool operator<=(const It &a, const It &b) { return !(a > b); }
};
NAMESPACE_BEGIN(iterator_policies)
/// Quick proxy class needed to implement ``operator->`` for iterators which can't return pointers
template <typename T>
struct arrow_proxy {
T value;
arrow_proxy(T &&value) : value(std::move(value)) { }
T *operator->() const { return &value; }
};
/// Lightweight iterator policy using just a simple pointer: see ``PySequence_Fast_ITEMS``
class sequence_fast_readonly {
protected:
using iterator_category = std::random_access_iterator_tag;
using value_type = handle;
using reference = const handle;
using pointer = arrow_proxy<const handle>;
sequence_fast_readonly(handle obj, ssize_t n) : ptr(PySequence_Fast_ITEMS(obj.ptr()) + n) { }
reference dereference() const { return *ptr; }
void increment() { ++ptr; }
void decrement() { --ptr; }
void advance(ssize_t n) { ptr += n; }
bool equal(const sequence_fast_readonly &b) const { return ptr == b.ptr; }
ssize_t distance_to(const sequence_fast_readonly &b) const { return ptr - b.ptr; }
private:
PyObject **ptr;
};
/// Full read and write access using the sequence protocol: see ``detail::sequence_accessor``
class sequence_slow_readwrite {
protected:
using iterator_category = std::random_access_iterator_tag;
using value_type = object;
using reference = sequence_accessor;
using pointer = arrow_proxy<const sequence_accessor>;
sequence_slow_readwrite(handle obj, ssize_t index) : obj(obj), index(index) { }
reference dereference() const { return {obj, static_cast<size_t>(index)}; }
void increment() { ++index; }
void decrement() { --index; }
void advance(ssize_t n) { index += n; }
bool equal(const sequence_slow_readwrite &b) const { return index == b.index; }
ssize_t distance_to(const sequence_slow_readwrite &b) const { return index - b.index; }
private:
handle obj;
ssize_t index;
};
/// Python's dictionary protocol permits this to be a forward iterator
class dict_readonly {
protected:
using iterator_category = std::forward_iterator_tag;
using value_type = std::pair<handle, handle>;
using reference = const value_type;
using pointer = arrow_proxy<const value_type>;
dict_readonly() = default;
dict_readonly(handle obj, ssize_t pos) : obj(obj), pos(pos) { increment(); }
reference dereference() const { return {key, value}; }
void increment() { if (!PyDict_Next(obj.ptr(), &pos, &key, &value)) { pos = -1; } }
bool equal(const dict_readonly &b) const { return pos == b.pos; }
private:
handle obj;
PyObject *key, *value;
ssize_t pos = -1;
};
NAMESPACE_END(iterator_policies)
#if !defined(PYPY_VERSION)
using tuple_iterator = generic_iterator<iterator_policies::sequence_fast_readonly>;
using list_iterator = generic_iterator<iterator_policies::sequence_fast_readonly>;
#else
using tuple_iterator = generic_iterator<iterator_policies::sequence_slow_readwrite>;
using list_iterator = generic_iterator<iterator_policies::sequence_slow_readwrite>;
#endif
using sequence_iterator = generic_iterator<iterator_policies::sequence_slow_readwrite>;
using dict_iterator = generic_iterator<iterator_policies::dict_readonly>;
inline bool PyIterable_Check(PyObject *obj) {
PyObject *iter = PyObject_GetIter(obj);
if (iter) {
Py_DECREF(iter);
return true;
} else {
PyErr_Clear();
return false;
}
}
inline bool PyNone_Check(PyObject *o) { return o == Py_None; }
inline bool PyUnicode_Check_Permissive(PyObject *o) { return PyUnicode_Check(o) || PYBIND11_BYTES_CHECK(o); }
class kwargs_proxy : public handle {
public:
explicit kwargs_proxy(handle h) : handle(h) { }
};
class args_proxy : public handle {
public:
explicit args_proxy(handle h) : handle(h) { }
kwargs_proxy operator*() const { return kwargs_proxy(*this); }
};
/// Python argument categories (using PEP 448 terms)
template <typename T> using is_keyword = std::is_base_of<arg, T>;
template <typename T> using is_s_unpacking = std::is_same<args_proxy, T>; // * unpacking
template <typename T> using is_ds_unpacking = std::is_same<kwargs_proxy, T>; // ** unpacking
template <typename T> using is_positional = satisfies_none_of<T,
is_keyword, is_s_unpacking, is_ds_unpacking
>;
template <typename T> using is_keyword_or_ds = satisfies_any_of<T, is_keyword, is_ds_unpacking>;
// Call argument collector forward declarations
template <return_value_policy policy = return_value_policy::automatic_reference>
class simple_collector;
template <return_value_policy policy = return_value_policy::automatic_reference>
class unpacking_collector;
NAMESPACE_END(detail)
// TODO: After the deprecated constructors are removed, this macro can be simplified by
// inheriting ctors: `using Parent::Parent`. It's not an option right now because
// the `using` statement triggers the parent deprecation warning even if the ctor
// isn't even used.
#define PYBIND11_OBJECT_COMMON(Name, Parent, CheckFun) \
public: \
PYBIND11_DEPRECATED("Use reinterpret_borrow<"#Name">() or reinterpret_steal<"#Name">()") \
Name(handle h, bool is_borrowed) : Parent(is_borrowed ? Parent(h, borrowed_t{}) : Parent(h, stolen_t{})) { } \
Name(handle h, borrowed_t) : Parent(h, borrowed_t{}) { } \
Name(handle h, stolen_t) : Parent(h, stolen_t{}) { } \
PYBIND11_DEPRECATED("Use py::isinstance<py::python_type>(obj) instead") \
bool check() const { return m_ptr != nullptr && (bool) CheckFun(m_ptr); } \
static bool check_(handle h) { return h.ptr() != nullptr && CheckFun(h.ptr()); }
#define PYBIND11_OBJECT_CVT(Name, Parent, CheckFun, ConvertFun) \
PYBIND11_OBJECT_COMMON(Name, Parent, CheckFun) \
/* This is deliberately not 'explicit' to allow implicit conversion from object: */ \
Name(const object &o) \
: Parent(check_(o) ? o.inc_ref().ptr() : ConvertFun(o.ptr()), stolen_t{}) \
{ if (!m_ptr) throw error_already_set(); } \
Name(object &&o) \
: Parent(check_(o) ? o.release().ptr() : ConvertFun(o.ptr()), stolen_t{}) \
{ if (!m_ptr) throw error_already_set(); } \
template <typename Policy_> \
Name(const ::pybind11::detail::accessor<Policy_> &a) : Name(object(a)) { }
#define PYBIND11_OBJECT(Name, Parent, CheckFun) \
PYBIND11_OBJECT_COMMON(Name, Parent, CheckFun) \
/* This is deliberately not 'explicit' to allow implicit conversion from object: */ \
Name(const object &o) : Parent(o) { } \
Name(object &&o) : Parent(std::move(o)) { }
#define PYBIND11_OBJECT_DEFAULT(Name, Parent, CheckFun) \
PYBIND11_OBJECT(Name, Parent, CheckFun) \
Name() : Parent() { }
/// \addtogroup pytypes
/// @{
/** \rst
Wraps a Python iterator so that it can also be used as a C++ input iterator
Caveat: copying an iterator does not (and cannot) clone the internal
state of the Python iterable. This also applies to the post-increment
operator. This iterator should only be used to retrieve the current
value using ``operator*()``.
\endrst */
class iterator : public object {
public:
using iterator_category = std::input_iterator_tag;
using difference_type = ssize_t;
using value_type = handle;
using reference = const handle;
using pointer = const handle *;
PYBIND11_OBJECT_DEFAULT(iterator, object, PyIter_Check)
iterator& operator++() {
advance();
return *this;
}
iterator operator++(int) {
auto rv = *this;
advance();
return rv;
}
reference operator*() const {
if (m_ptr && !value.ptr()) {
auto& self = const_cast<iterator &>(*this);
self.advance();
}
return value;
}
pointer operator->() const { operator*(); return &value; }
/** \rst
The value which marks the end of the iteration. ``it == iterator::sentinel()``
is equivalent to catching ``StopIteration`` in Python.
.. code-block:: cpp
void foo(py::iterator it) {
while (it != py::iterator::sentinel()) {
// use `*it`
++it;
}
}
\endrst */
static iterator sentinel() { return {}; }
friend bool operator==(const iterator &a, const iterator &b) { return a->ptr() == b->ptr(); }
friend bool operator!=(const iterator &a, const iterator &b) { return a->ptr() != b->ptr(); }
private:
void advance() {
value = reinterpret_steal<object>(PyIter_Next(m_ptr));
if (PyErr_Occurred()) { throw error_already_set(); }
}
private:
object value = {};
};
class iterable : public object {
public:
PYBIND11_OBJECT_DEFAULT(iterable, object, detail::PyIterable_Check)
};
class bytes;
class str : public object {
public:
PYBIND11_OBJECT_CVT(str, object, detail::PyUnicode_Check_Permissive, raw_str)
str(const char *c, size_t n)
: object(PyUnicode_FromStringAndSize(c, (ssize_t) n), stolen_t{}) {
if (!m_ptr) pybind11_fail("Could not allocate string object!");
}
// 'explicit' is explicitly omitted from the following constructors to allow implicit conversion to py::str from C++ string-like objects
str(const char *c = "")
: object(PyUnicode_FromString(c), stolen_t{}) {
if (!m_ptr) pybind11_fail("Could not allocate string object!");
}
str(const std::string &s) : str(s.data(), s.size()) { }
explicit str(const bytes &b);
/** \rst
Return a string representation of the object. This is analogous to
the ``str()`` function in Python.
\endrst */
explicit str(handle h) : object(raw_str(h.ptr()), stolen_t{}) { }
operator std::string() const {
object temp = *this;
if (PyUnicode_Check(m_ptr)) {
temp = reinterpret_steal<object>(PyUnicode_AsUTF8String(m_ptr));
if (!temp)
pybind11_fail("Unable to extract string contents! (encoding issue)");
}
char *buffer;
ssize_t length;
if (PYBIND11_BYTES_AS_STRING_AND_SIZE(temp.ptr(), &buffer, &length))
pybind11_fail("Unable to extract string contents! (invalid type)");
return std::string(buffer, (size_t) length);
}
template <typename... Args>
str format(Args &&...args) const {
return attr("format")(std::forward<Args>(args)...);
}
private:
/// Return string representation -- always returns a new reference, even if already a str
static PyObject *raw_str(PyObject *op) {
PyObject *str_value = PyObject_Str(op);
#if PY_MAJOR_VERSION < 3
if (!str_value) throw error_already_set();
PyObject *unicode = PyUnicode_FromEncodedObject(str_value, "utf-8", nullptr);
Py_XDECREF(str_value); str_value = unicode;
#endif
return str_value;
}
};
/// @} pytypes
inline namespace literals {
/** \rst
String literal version of `str`
\endrst */
inline str operator"" _s(const char *s, size_t size) { return {s, size}; }
}
/// \addtogroup pytypes
/// @{
class bytes : public object {
public:
PYBIND11_OBJECT(bytes, object, PYBIND11_BYTES_CHECK)
// Allow implicit conversion:
bytes(const char *c = "")
: object(PYBIND11_BYTES_FROM_STRING(c), stolen_t{}) {
if (!m_ptr) pybind11_fail("Could not allocate bytes object!");
}
bytes(const char *c, size_t n)
: object(PYBIND11_BYTES_FROM_STRING_AND_SIZE(c, (ssize_t) n), stolen_t{}) {
if (!m_ptr) pybind11_fail("Could not allocate bytes object!");
}
// Allow implicit conversion:
bytes(const std::string &s) : bytes(s.data(), s.size()) { }
explicit bytes(const pybind11::str &s);
operator std::string() const {
char *buffer;
ssize_t length;
if (PYBIND11_BYTES_AS_STRING_AND_SIZE(m_ptr, &buffer, &length))
pybind11_fail("Unable to extract bytes contents!");
return std::string(buffer, (size_t) length);
}
};
inline bytes::bytes(const pybind11::str &s) {
object temp = s;
if (PyUnicode_Check(s.ptr())) {
temp = reinterpret_steal<object>(PyUnicode_AsUTF8String(s.ptr()));
if (!temp)
pybind11_fail("Unable to extract string contents! (encoding issue)");
}
char *buffer;
ssize_t length;
if (PYBIND11_BYTES_AS_STRING_AND_SIZE(temp.ptr(), &buffer, &length))
pybind11_fail("Unable to extract string contents! (invalid type)");
auto obj = reinterpret_steal<object>(PYBIND11_BYTES_FROM_STRING_AND_SIZE(buffer, length));
if (!obj)
pybind11_fail("Could not allocate bytes object!");
m_ptr = obj.release().ptr();
}
inline str::str(const bytes& b) {
char *buffer;
ssize_t length;
if (PYBIND11_BYTES_AS_STRING_AND_SIZE(b.ptr(), &buffer, &length))
pybind11_fail("Unable to extract bytes contents!");
auto obj = reinterpret_steal<object>(PyUnicode_FromStringAndSize(buffer, (ssize_t) length));
if (!obj)
pybind11_fail("Could not allocate string object!");
m_ptr = obj.release().ptr();
}
class none : public object {
public:
PYBIND11_OBJECT(none, object, detail::PyNone_Check)
none() : object(Py_None, borrowed_t{}) { }
};
class bool_ : public object {
public:
PYBIND11_OBJECT_CVT(bool_, object, PyBool_Check, raw_bool)
bool_() : object(Py_False, borrowed_t{}) { }
// Allow implicit conversion from and to `bool`:
bool_(bool value) : object(value ? Py_True : Py_False, borrowed_t{}) { }
operator bool() const { return m_ptr && PyLong_AsLong(m_ptr) != 0; }
private:
/// Return the truth value of an object -- always returns a new reference
static PyObject *raw_bool(PyObject *op) {
const auto value = PyObject_IsTrue(op);
if (value == -1) return nullptr;
return handle(value ? Py_True : Py_False).inc_ref().ptr();
}
};
NAMESPACE_BEGIN(detail)
// Converts a value to the given unsigned type. If an error occurs, you get back (Unsigned) -1;
// otherwise you get back the unsigned long or unsigned long long value cast to (Unsigned).
// (The distinction is critically important when casting a returned -1 error value to some other
// unsigned type: (A)-1 != (B)-1 when A and B are unsigned types of different sizes).
template <typename Unsigned>
Unsigned as_unsigned(PyObject *o) {
if (sizeof(Unsigned) <= sizeof(unsigned long)
#if PY_VERSION_HEX < 0x03000000
|| PyInt_Check(o)
#endif
) {
unsigned long v = PyLong_AsUnsignedLong(o);
return v == (unsigned long) -1 && PyErr_Occurred() ? (Unsigned) -1 : (Unsigned) v;
}
else {
unsigned long long v = PyLong_AsUnsignedLongLong(o);
return v == (unsigned long long) -1 && PyErr_Occurred() ? (Unsigned) -1 : (Unsigned) v;
}
}
NAMESPACE_END(detail)
class int_ : public object {
public:
PYBIND11_OBJECT_CVT(int_, object, PYBIND11_LONG_CHECK, PyNumber_Long)
int_() : object(PyLong_FromLong(0), stolen_t{}) { }
// Allow implicit conversion from C++ integral types:
template <typename T,
detail::enable_if_t<std::is_integral<T>::value, int> = 0>
int_(T value) {
if (sizeof(T) <= sizeof(long)) {
if (std::is_signed<T>::value)
m_ptr = PyLong_FromLong((long) value);
else
m_ptr = PyLong_FromUnsignedLong((unsigned long) value);
} else {
if (std::is_signed<T>::value)
m_ptr = PyLong_FromLongLong((long long) value);
else
m_ptr = PyLong_FromUnsignedLongLong((unsigned long long) value);
}
if (!m_ptr) pybind11_fail("Could not allocate int object!");
}
template <typename T,
detail::enable_if_t<std::is_integral<T>::value, int> = 0>
operator T() const {
return std::is_unsigned<T>::value
? detail::as_unsigned<T>(m_ptr)
: sizeof(T) <= sizeof(long)
? (T) PyLong_AsLong(m_ptr)
: (T) PYBIND11_LONG_AS_LONGLONG(m_ptr);
}
};
class float_ : public object {
public:
PYBIND11_OBJECT_CVT(float_, object, PyFloat_Check, PyNumber_Float)
// Allow implicit conversion from float/double:
float_(float value) : object(PyFloat_FromDouble((double) value), stolen_t{}) {
if (!m_ptr) pybind11_fail("Could not allocate float object!");
}
float_(double value = .0) : object(PyFloat_FromDouble((double) value), stolen_t{}) {
if (!m_ptr) pybind11_fail("Could not allocate float object!");
}
operator float() const { return (float) PyFloat_AsDouble(m_ptr); }
operator double() const { return (double) PyFloat_AsDouble(m_ptr); }
};
class weakref : public object {
public:
PYBIND11_OBJECT_DEFAULT(weakref, object, PyWeakref_Check)
explicit weakref(handle obj, handle callback = {})
: object(PyWeakref_NewRef(obj.ptr(), callback.ptr()), stolen_t{}) {
if (!m_ptr) pybind11_fail("Could not allocate weak reference!");
}
};
class slice : public object {
public:
PYBIND11_OBJECT_DEFAULT(slice, object, PySlice_Check)
slice(ssize_t start_, ssize_t stop_, ssize_t step_) {
int_ start(start_), stop(stop_), step(step_);
m_ptr = PySlice_New(start.ptr(), stop.ptr(), step.ptr());
if (!m_ptr) pybind11_fail("Could not allocate slice object!");
}
bool compute(size_t length, size_t *start, size_t *stop, size_t *step,
size_t *slicelength) const {
return PySlice_GetIndicesEx((PYBIND11_SLICE_OBJECT *) m_ptr,
(ssize_t) length, (ssize_t *) start,
(ssize_t *) stop, (ssize_t *) step,
(ssize_t *) slicelength) == 0;
}
};
class capsule : public object {
public:
PYBIND11_OBJECT_DEFAULT(capsule, object, PyCapsule_CheckExact)
PYBIND11_DEPRECATED("Use reinterpret_borrow<capsule>() or reinterpret_steal<capsule>()")
capsule(PyObject *ptr, bool is_borrowed) : object(is_borrowed ? object(ptr, borrowed_t{}) : object(ptr, stolen_t{})) { }
explicit capsule(const void *value, const char *name = nullptr, void (*destructor)(PyObject *) = nullptr)
: object(PyCapsule_New(const_cast<void *>(value), name, destructor), stolen_t{}) {
if (!m_ptr)
pybind11_fail("Could not allocate capsule object!");
}
PYBIND11_DEPRECATED("Please pass a destructor that takes a void pointer as input")
capsule(const void *value, void (*destruct)(PyObject *))
: object(PyCapsule_New(const_cast<void*>(value), nullptr, destruct), stolen_t{}) {
if (!m_ptr)
pybind11_fail("Could not allocate capsule object!");
}
capsule(const void *value, void (*destructor)(void *)) {
m_ptr = PyCapsule_New(const_cast<void *>(value), nullptr, [](PyObject *o) {
auto destructor = reinterpret_cast<void (*)(void *)>(PyCapsule_GetContext(o));
void *ptr = PyCapsule_GetPointer(o, nullptr);
destructor(ptr);
});
if (!m_ptr)
pybind11_fail("Could not allocate capsule object!");
if (PyCapsule_SetContext(m_ptr, (void *) destructor) != 0)
pybind11_fail("Could not set capsule context!");
}
capsule(void (*destructor)()) {
m_ptr = PyCapsule_New(reinterpret_cast<void *>(destructor), nullptr, [](PyObject *o) {
auto destructor = reinterpret_cast<void (*)()>(PyCapsule_GetPointer(o, nullptr));
destructor();
});
if (!m_ptr)
pybind11_fail("Could not allocate capsule object!");
}
template <typename T> operator T *() const {
auto name = this->name();
T * result = static_cast<T *>(PyCapsule_GetPointer(m_ptr, name));
if (!result) pybind11_fail("Unable to extract capsule contents!");
return result;
}
const char *name() const { return PyCapsule_GetName(m_ptr); }
};
class tuple : public object {
public:
PYBIND11_OBJECT_CVT(tuple, object, PyTuple_Check, PySequence_Tuple)
explicit tuple(size_t size = 0) : object(PyTuple_New((ssize_t) size), stolen_t{}) {
if (!m_ptr) pybind11_fail("Could not allocate tuple object!");
}
size_t size() const { return (size_t) PyTuple_Size(m_ptr); }
detail::tuple_accessor operator[](size_t index) const { return {*this, index}; }
detail::tuple_iterator begin() const { return {*this, 0}; }
detail::tuple_iterator end() const { return {*this, PyTuple_GET_SIZE(m_ptr)}; }
};
class dict : public object {
public:
PYBIND11_OBJECT_CVT(dict, object, PyDict_Check, raw_dict)
dict() : object(PyDict_New(), stolen_t{}) {
if (!m_ptr) pybind11_fail("Could not allocate dict object!");
}
template <typename... Args,
typename = detail::enable_if_t<detail::all_of<detail::is_keyword_or_ds<Args>...>::value>,
// MSVC workaround: it can't compile an out-of-line definition, so defer the collector
typename collector = detail::deferred_t<detail::unpacking_collector<>, Args...>>
explicit dict(Args &&...args) : dict(collector(std::forward<Args>(args)...).kwargs()) { }
size_t size() const { return (size_t) PyDict_Size(m_ptr); }
detail::dict_iterator begin() const { return {*this, 0}; }
detail::dict_iterator end() const { return {}; }
void clear() const { PyDict_Clear(ptr()); }
bool contains(handle key) const { return PyDict_Contains(ptr(), key.ptr()) == 1; }
bool contains(const char *key) const { return PyDict_Contains(ptr(), pybind11::str(key).ptr()) == 1; }
private:
/// Call the `dict` Python type -- always returns a new reference
static PyObject *raw_dict(PyObject *op) {
if (PyDict_Check(op))
return handle(op).inc_ref().ptr();
return PyObject_CallFunctionObjArgs((PyObject *) &PyDict_Type, op, nullptr);
}
};
class sequence : public object {
public:
PYBIND11_OBJECT_DEFAULT(sequence, object, PySequence_Check)
size_t size() const { return (size_t) PySequence_Size(m_ptr); }
detail::sequence_accessor operator[](size_t index) const { return {*this, index}; }
detail::sequence_iterator begin() const { return {*this, 0}; }
detail::sequence_iterator end() const { return {*this, PySequence_Size(m_ptr)}; }
};
class list : public object {
public:
PYBIND11_OBJECT_CVT(list, object, PyList_Check, PySequence_List)
explicit list(size_t size = 0) : object(PyList_New((ssize_t) size), stolen_t{}) {
if (!m_ptr) pybind11_fail("Could not allocate list object!");
}
size_t size() const { return (size_t) PyList_Size(m_ptr); }
detail::list_accessor operator[](size_t index) const { return {*this, index}; }
detail::list_iterator begin() const { return {*this, 0}; }
detail::list_iterator end() const { return {*this, PyList_GET_SIZE(m_ptr)}; }
template <typename T> void append(T &&val) const {
PyList_Append(m_ptr, detail::object_or_cast(std::forward<T>(val)).ptr());
}
};
class args : public tuple { PYBIND11_OBJECT_DEFAULT(args, tuple, PyTuple_Check) };
class kwargs : public dict { PYBIND11_OBJECT_DEFAULT(kwargs, dict, PyDict_Check) };
class set : public object {
public:
PYBIND11_OBJECT_CVT(set, object, PySet_Check, PySet_New)
set() : object(PySet_New(nullptr), stolen_t{}) {
if (!m_ptr) pybind11_fail("Could not allocate set object!");
}
size_t size() const { return (size_t) PySet_Size(m_ptr); }
template <typename T> bool add(T &&val) const {
return PySet_Add(m_ptr, detail::object_or_cast(std::forward<T>(val)).ptr()) == 0;
}
void clear() const { PySet_Clear(m_ptr); }
};
class function : public object {
public:
PYBIND11_OBJECT_DEFAULT(function, object, PyCallable_Check)
handle cpp_function() const {
handle fun = detail::get_function(m_ptr);
if (fun && PyCFunction_Check(fun.ptr()))
return fun;
return handle();
}
bool is_cpp_function() const { return (bool) cpp_function(); }
};
class buffer : public object {
public:
PYBIND11_OBJECT_DEFAULT(buffer, object, PyObject_CheckBuffer)
buffer_info request(bool writable = false) {
int flags = PyBUF_STRIDES | PyBUF_FORMAT;
if (writable) flags |= PyBUF_WRITABLE;
Py_buffer *view = new Py_buffer();
if (PyObject_GetBuffer(m_ptr, view, flags) != 0) {
delete view;
throw error_already_set();
}
return buffer_info(view);
}
};
class memoryview : public object {
public:
explicit memoryview(const buffer_info& info) {
static Py_buffer buf { };
// Py_buffer uses signed sizes, strides and shape!..
static std::vector<Py_ssize_t> py_strides { };
static std::vector<Py_ssize_t> py_shape { };
buf.buf = info.ptr;
buf.itemsize = info.itemsize;
buf.format = const_cast<char *>(info.format.c_str());
buf.ndim = (int) info.ndim;
buf.len = info.size;
py_strides.clear();
py_shape.clear();
for (size_t i = 0; i < (size_t) info.ndim; ++i) {
py_strides.push_back(info.strides[i]);
py_shape.push_back(info.shape[i]);
}
buf.strides = py_strides.data();
buf.shape = py_shape.data();
buf.suboffsets = nullptr;
buf.readonly = false;
buf.internal = nullptr;
m_ptr = PyMemoryView_FromBuffer(&buf);
if (!m_ptr)
pybind11_fail("Unable to create memoryview from buffer descriptor");
}
PYBIND11_OBJECT_CVT(memoryview, object, PyMemoryView_Check, PyMemoryView_FromObject)
};
/// @} pytypes
/// \addtogroup python_builtins
/// @{
inline size_t len(handle h) {
ssize_t result = PyObject_Length(h.ptr());
if (result < 0)
pybind11_fail("Unable to compute length of object");
return (size_t) result;
}
inline str repr(handle h) {
PyObject *str_value = PyObject_Repr(h.ptr());
if (!str_value) throw error_already_set();
#if PY_MAJOR_VERSION < 3
PyObject *unicode = PyUnicode_FromEncodedObject(str_value, "utf-8", nullptr);
Py_XDECREF(str_value); str_value = unicode;
if (!str_value) throw error_already_set();
#endif
return reinterpret_steal<str>(str_value);
}
inline iterator iter(handle obj) {
PyObject *result = PyObject_GetIter(obj.ptr());
if (!result) { throw error_already_set(); }
return reinterpret_steal<iterator>(result);
}
/// @} python_builtins
NAMESPACE_BEGIN(detail)
template <typename D> iterator object_api<D>::begin() const { return iter(derived()); }
template <typename D> iterator object_api<D>::end() const { return iterator::sentinel(); }
template <typename D> item_accessor object_api<D>::operator[](handle key) const {
return {derived(), reinterpret_borrow<object>(key)};
}
template <typename D> item_accessor object_api<D>::operator[](const char *key) const {
return {derived(), pybind11::str(key)};
}
template <typename D> obj_attr_accessor object_api<D>::attr(handle key) const {
return {derived(), reinterpret_borrow<object>(key)};
}
template <typename D> str_attr_accessor object_api<D>::attr(const char *key) const {
return {derived(), key};
}
template <typename D> args_proxy object_api<D>::operator*() const {
return args_proxy(derived().ptr());
}
template <typename D> template <typename T> bool object_api<D>::contains(T &&item) const {
return attr("__contains__")(std::forward<T>(item)).template cast<bool>();
}
template <typename D>
pybind11::str object_api<D>::str() const { return pybind11::str(derived()); }
template <typename D>
str_attr_accessor object_api<D>::doc() const { return attr("__doc__"); }
template <typename D>
handle object_api<D>::get_type() const { return (PyObject *) Py_TYPE(derived().ptr()); }
NAMESPACE_END(detail)
NAMESPACE_END(PYBIND11_NAMESPACE)