Add default and converting constructors for all concrete Python types

* Deprecate the `py::object::str()` member function since `py::str(obj)`
  is now equivalent and preferred

* Make `py::repr()` a free function

* Make sure obj.cast<T>() works as expected when T is a Python type

`obj.cast<T>()` should be the same as `T(obj)`, i.e. it should convert
the given object to a different Python type. However, `obj.cast<T>()`
usually calls `type_caster::load()` which only checks the type without
doing any actual conversion. That causes a very unexpected `cast_error`.
This commit makes it so that `obj.cast<T>()` and `T(obj)` are the same
when T is a Python type.

* Simplify pytypes converting constructor implementation

It's not necessary to maintain a full set of converting constructors
and assignment operators + const& and &&. A single converting const&
constructor will work and there is no impact on binary size. On the
other hand, the conversion functions can be significantly simplified.
This commit is contained in:
Dean Moldovan 2016-10-25 22:12:39 +02:00 committed by Wenzel Jakob
parent b4498ef44d
commit e18bc02fc9
11 changed files with 179 additions and 99 deletions

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@ -28,7 +28,7 @@ Breaking changes queued for v2.0.0 (Not yet released)
(now uses prefix increment operator); it now also accepts iterators with
different begin/end types as long as they are equality comparable.
* ``arg()`` now accepts a wider range of argument types for default values
* Added ``repr()`` method to the ``handle`` class.
* Added ``py::repr()`` function which is equivalent to Python's builtin ``repr()``.
* Added support for registering structured dtypes via ``PYBIND11_NUMPY_DTYPE()`` macro.
* Added ``PYBIND11_STR_TYPE`` macro which maps to the ``builtins.str`` type.
* Added a simplified ``buffer_info`` constructor for 1-dimensional buffers.

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@ -265,9 +265,9 @@ template <> struct process_attribute<arg_v> : process_attribute_default<arg_v> {
auto descr = "'" + std::string(a.name) + ": " + a.type + "'";
if (r->class_) {
if (r->name)
descr += " in method '" + (std::string) r->class_.str() + "." + (std::string) r->name + "'";
descr += " in method '" + (std::string) str(r->class_) + "." + (std::string) r->name + "'";
else
descr += " in method of '" + (std::string) r->class_.str() + "'";
descr += " in method of '" + (std::string) str(r->class_) + "'";
} else if (r->name) {
descr += " in function named '" + (std::string) r->name + "'";
}

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@ -132,7 +132,7 @@ PYBIND11_NOINLINE inline std::string error_string() {
errorString += ": ";
}
if (scope.value)
errorString += (std::string) handle(scope.value).str();
errorString += (std::string) str(scope.value);
PyErr_NormalizeException(&scope.type, &scope.value, &scope.trace);
@ -1056,7 +1056,7 @@ template <typename T, typename SFINAE> type_caster<T, SFINAE> &load_type(type_ca
throw cast_error("Unable to cast Python instance to C++ type (compile in debug mode for details)");
#else
throw cast_error("Unable to cast Python instance of type " +
(std::string) handle.get_type().str() + " to C++ type '" + type_id<T>() + "''");
(std::string) str(handle.get_type()) + " to C++ type '" + type_id<T>() + "''");
#endif
}
return conv;
@ -1070,15 +1070,19 @@ template <typename T> make_caster<T> load_type(const handle &handle) {
NAMESPACE_END(detail)
template <typename T> T cast(const handle &handle) {
template <typename T, detail::enable_if_t<!detail::is_pyobject<T>::value, int> = 0>
T cast(const handle &handle) {
static_assert(!detail::cast_is_temporary_value_reference<T>::value,
"Unable to cast type to reference: value is local to type caster");
using type_caster = detail::make_caster<T>;
return detail::load_type<T>(handle).operator typename type_caster::template cast_op_type<T>();
}
template <typename T> object cast(const T &value,
return_value_policy policy = return_value_policy::automatic_reference,
template <typename T, detail::enable_if_t<detail::is_pyobject<T>::value, int> = 0>
T cast(const handle &handle) { return {handle, true}; }
template <typename T, detail::enable_if_t<!detail::is_pyobject<T>::value, int> = 0>
object cast(const T &value, return_value_policy policy = return_value_policy::automatic_reference,
handle parent = handle()) {
if (policy == return_value_policy::automatic)
policy = std::is_pointer<T>::value ? return_value_policy::take_ownership : return_value_policy::copy;
@ -1097,7 +1101,7 @@ detail::enable_if_t<detail::move_always<T>::value || detail::move_if_unreference
throw cast_error("Unable to cast Python instance to C++ rvalue: instance has multiple references"
" (compile in debug mode for details)");
#else
throw cast_error("Unable to move from Python " + (std::string) obj.get_type().str() +
throw cast_error("Unable to move from Python " + (std::string) str(obj.get_type()) +
" instance to C++ " + type_id<T>() + " instance: instance has multiple references");
#endif
@ -1274,7 +1278,7 @@ public:
int _[] = { 0, (process(args_list, std::forward<Ts>(values)), 0)... };
ignore_unused(_);
m_args = object(PyList_AsTuple(args_list.ptr()), false);
m_args = std::move(args_list);
}
const tuple &args() const & { return m_args; }
@ -1336,7 +1340,7 @@ private:
#if defined(NDEBUG)
multiple_values_error();
#else
multiple_values_error(k.first.str());
multiple_values_error(str(k.first));
#endif
}
m_kwargs[k.first] = k.second;

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@ -111,7 +111,6 @@
#define PYBIND11_BYTES_FROM_STRING_AND_SIZE PyBytes_FromStringAndSize
#define PYBIND11_BYTES_AS_STRING_AND_SIZE PyBytes_AsStringAndSize
#define PYBIND11_BYTES_AS_STRING PyBytes_AsString
#define PYBIND11_BYTES_CHECK PyBytes_Check
#define PYBIND11_LONG_CHECK(o) PyLong_Check(o)
#define PYBIND11_LONG_AS_LONGLONG(o) PyLong_AsLongLong(o)
#define PYBIND11_LONG_AS_UNSIGNED_LONGLONG(o) PyLong_AsUnsignedLongLong(o)
@ -130,7 +129,6 @@
#define PYBIND11_BYTES_FROM_STRING_AND_SIZE PyString_FromStringAndSize
#define PYBIND11_BYTES_AS_STRING_AND_SIZE PyString_AsStringAndSize
#define PYBIND11_BYTES_AS_STRING PyString_AsString
#define PYBIND11_BYTES_CHECK PyString_Check
#define PYBIND11_LONG_CHECK(o) (PyInt_Check(o) || PyLong_Check(o))
#define PYBIND11_LONG_AS_LONGLONG(o) (PyInt_Check(o) ? (long long) PyLong_AsLong(o) : PyLong_AsLongLong(o))
#define PYBIND11_LONG_AS_UNSIGNED_LONGLONG(o) (PyInt_Check(o) ? (unsigned long long) PyLong_AsUnsignedLong(o) : PyLong_AsUnsignedLongLong(o))

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@ -540,10 +540,12 @@ protected:
template <typename T, int ExtraFlags = array::forcecast> class array_t : public array {
public:
PYBIND11_OBJECT_CVT(array_t, array, is_non_null, m_ptr = ensure_(m_ptr));
array_t() : array() { }
array_t(handle h, bool borrowed) : array(h, borrowed) { m_ptr = ensure_(m_ptr); }
array_t(const object &o) : array(o) { m_ptr = ensure_(m_ptr); }
explicit array_t(const buffer_info& info) : array(info) { }
array_t(const std::vector<size_t> &shape,
@ -588,8 +590,6 @@ public:
return *(static_cast<T*>(array::mutable_data()) + byte_offset(size_t(index)...) / itemsize());
}
static bool is_non_null(PyObject *ptr) { return ptr != nullptr; }
static PyObject *ensure_(PyObject *ptr) {
if (ptr == nullptr)
return nullptr;

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@ -504,7 +504,7 @@ protected:
msg += "\nInvoked with: ";
tuple args_(args, true);
for (size_t ti = overloads->is_constructor ? 1 : 0; ti < args_.size(); ++ti) {
msg += static_cast<std::string>(static_cast<object>(args_[ti]).str());
msg += static_cast<std::string>(pybind11::str(args_[ti]));
if ((ti + 1) != args_.size() )
msg += ", ";
}
@ -665,11 +665,9 @@ protected:
#endif
size_t num_bases = rec->bases.size();
tuple bases(num_bases);
for (size_t i = 0; i < num_bases; ++i)
bases[i] = rec->bases[i];
auto bases = tuple(rec->bases);
std::string full_name = (scope_module ? ((std::string) scope_module.str() + "." + rec->name)
std::string full_name = (scope_module ? ((std::string) pybind11::str(scope_module) + "." + rec->name)
: std::string(rec->name));
char *tp_doc = nullptr;
@ -1470,7 +1468,7 @@ NAMESPACE_BEGIN(detail)
PYBIND11_NOINLINE inline void print(tuple args, dict kwargs) {
auto strings = tuple(args.size());
for (size_t i = 0; i < args.size(); ++i) {
strings[i] = args[i].str();
strings[i] = str(args[i]);
}
auto sep = kwargs.contains("sep") ? kwargs["sep"] : cast(" ");
auto line = sep.attr("join")(strings);
@ -1654,7 +1652,7 @@ inline function get_type_overload(const void *this_ptr, const detail::type_info
/* Don't call dispatch code if invoked from overridden function */
PyFrameObject *frame = PyThreadState_Get()->frame;
if (frame && (std::string) pybind11::handle(frame->f_code->co_name).str() == name &&
if (frame && (std::string) str(frame->f_code->co_name) == name &&
frame->f_code->co_argcount > 0) {
PyFrame_FastToLocals(frame);
PyObject *self_caller = PyDict_GetItem(

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@ -68,8 +68,8 @@ public:
object call(Args&&... args) const;
bool is_none() const { return derived().ptr() == Py_None; }
PYBIND11_DEPRECATED("Instead of obj.str(), use py::str(obj)")
pybind11::str str() const;
pybind11::str repr() const;
int ref_count() const { return static_cast<int>(Py_REFCNT(derived().ptr())); }
handle get_type() const;
@ -222,13 +222,13 @@ public:
template <typename T = Policy>
PYBIND11_DEPRECATED("Use of obj.attr(...) as bool is deprecated in favor of pybind11::hasattr(obj, ...)")
operator enable_if_t<std::is_same<T, accessor_policies::str_attr>::value ||
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)")
operator enable_if_t<std::is_same<T, accessor_policies::generic_item>::value, bool>() const {
explicit operator enable_if_t<std::is_same<T, accessor_policies::generic_item>::value, bool>() const {
return obj.contains(key);
}
@ -390,20 +390,23 @@ class unpacking_collector;
NAMESPACE_END(detail)
#define PYBIND11_OBJECT_CVT(Name, Parent, CheckFun, CvtStmt) \
#define PYBIND11_OBJECT_COMMON(Name, Parent, CheckFun) \
public: \
Name(const handle &h, bool borrowed) : Parent(h, borrowed) { CvtStmt; } \
/* These are deliberately not 'explicit' to allow implicit conversion from object: */ \
Name(const object& o): Parent(o) { CvtStmt; } \
Name(object&& o) noexcept : Parent(std::move(o)) { CvtStmt; } \
Name& operator=(object&& o) noexcept { (void) object::operator=(std::move(o)); CvtStmt; return *this; } \
Name& operator=(const object& o) { return static_cast<Name&>(object::operator=(o)); CvtStmt; } \
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) \
Name(handle h, bool borrowed) : Name(object(h, borrowed)) { } \
/* This is deliberately not 'explicit' to allow implicit conversion from object: */ \
Name(const object &o) : Parent(ConvertFun(o.ptr()), false) { if (!m_ptr) throw error_already_set(); }
#define PYBIND11_OBJECT(Name, Parent, CheckFun) \
PYBIND11_OBJECT_CVT(Name, Parent, CheckFun, )
PYBIND11_OBJECT_COMMON(Name, Parent, CheckFun) \
Name(handle h, bool borrowed) : Parent(h, borrowed) { } \
/* This is deliberately not 'explicit' to allow implicit conversion from object: */ \
Name(const object &o) : Parent(o) { }
#define PYBIND11_OBJECT_DEFAULT(Name, Parent, CheckFun) \
PYBIND11_OBJECT(Name, Parent, CheckFun) \
@ -411,26 +414,9 @@ NAMESPACE_END(detail)
class iterator : public object {
public:
PYBIND11_OBJECT_CVT(iterator, object, PyIter_Check, value = object(); ready = false)
iterator() : object(), value(object()), ready(false) { }
iterator(const iterator& it) : object(it), value(it.value), ready(it.ready) { }
iterator(iterator&& it) : object(std::move(it)), value(std::move(it.value)), ready(it.ready) { }
/** Caveat: this copy constructor does not (and cannot) clone the internal
/** Caveat: copying an iterator does not (and cannot) clone the internal
state of the Python iterable */
iterator &operator=(const iterator &it) {
(void) object::operator=(it);
value = it.value;
ready = it.ready;
return *this;
}
iterator &operator=(iterator &&it) noexcept {
(void) object::operator=(std::move(it));
value = std::move(it.value);
ready = it.ready;
return *this;
}
PYBIND11_OBJECT_DEFAULT(iterator, object, PyIter_Check)
iterator& operator++() {
if (m_ptr)
@ -465,8 +451,8 @@ private:
void advance() { value = object(PyIter_Next(m_ptr), false); }
private:
object value;
bool ready;
object value = {};
bool ready = false;
};
class iterable : public object {
@ -478,7 +464,7 @@ class bytes;
class str : public object {
public:
PYBIND11_OBJECT_DEFAULT(str, object, detail::PyUnicode_Check_Permissive)
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), false) {
@ -486,7 +472,7 @@ public:
}
// 'explicit' is explicitly omitted from the following constructors to allow implicit conversion to py::str from C++ string-like objects
str(const char *c)
str(const char *c = "")
: object(PyUnicode_FromString(c), false) {
if (!m_ptr) pybind11_fail("Could not allocate string object!");
}
@ -495,6 +481,8 @@ public:
explicit str(const bytes &b);
explicit str(handle h) : object(raw_str(h.ptr()), false) { }
operator std::string() const {
object temp = *this;
if (PyUnicode_Check(m_ptr)) {
@ -513,6 +501,18 @@ public:
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;
}
};
inline namespace literals {
@ -522,10 +522,10 @@ inline str operator"" _s(const char *s, size_t size) { return {s, size}; }
class bytes : public object {
public:
PYBIND11_OBJECT_DEFAULT(bytes, object, PYBIND11_BYTES_CHECK)
PYBIND11_OBJECT(bytes, object, PYBIND11_BYTES_CHECK)
// Allow implicit conversion:
bytes(const char *c)
bytes(const char *c = "")
: object(PYBIND11_BYTES_FROM_STRING(c), false) {
if (!m_ptr) pybind11_fail("Could not allocate bytes object!");
}
@ -585,15 +585,25 @@ public:
class bool_ : public object {
public:
PYBIND11_OBJECT_DEFAULT(bool_, object, PyBool_Check)
PYBIND11_OBJECT_CVT(bool_, object, PyBool_Check, raw_bool)
bool_() : object(Py_False, true) { }
// Allow implicit conversion from and to `bool`:
bool_(bool value) : object(value ? Py_True : Py_False, true) { }
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();
}
};
class int_ : public object {
public:
PYBIND11_OBJECT_DEFAULT(int_, object, PYBIND11_LONG_CHECK)
PYBIND11_OBJECT_CVT(int_, object, PYBIND11_LONG_CHECK, PyNumber_Long)
int_() : object(PyLong_FromLong(0), false) { }
// Allow implicit conversion from C++ integral types:
template <typename T,
detail::enable_if_t<std::is_integral<T>::value, int> = 0>
@ -631,12 +641,12 @@ public:
class float_ : public object {
public:
PYBIND11_OBJECT_DEFAULT(float_, object, PyFloat_Check)
PYBIND11_OBJECT_CVT(float_, object, PyFloat_Check, PyNumber_Float)
// Allow implicit conversion from float/double:
float_(float value) : object(PyFloat_FromDouble((double) value), false) {
if (!m_ptr) pybind11_fail("Could not allocate float object!");
}
float_(double value) : object(PyFloat_FromDouble((double) value), false) {
float_(double value = .0) : object(PyFloat_FromDouble((double) value), false) {
if (!m_ptr) pybind11_fail("Could not allocate float object!");
}
operator float() const { return (float) PyFloat_AsDouble(m_ptr); }
@ -685,7 +695,7 @@ public:
class tuple : public object {
public:
PYBIND11_OBJECT(tuple, object, PyTuple_Check)
PYBIND11_OBJECT_CVT(tuple, object, PyTuple_Check, PySequence_Tuple)
explicit tuple(size_t size = 0) : object(PyTuple_New((ssize_t) size), false) {
if (!m_ptr) pybind11_fail("Could not allocate tuple object!");
}
@ -695,7 +705,7 @@ public:
class dict : public object {
public:
PYBIND11_OBJECT(dict, object, PyDict_Check)
PYBIND11_OBJECT_CVT(dict, object, PyDict_Check, raw_dict)
dict() : object(PyDict_New(), false) {
if (!m_ptr) pybind11_fail("Could not allocate dict object!");
}
@ -711,6 +721,14 @@ public:
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 {
@ -722,7 +740,7 @@ public:
class list : public object {
public:
PYBIND11_OBJECT(list, object, PyList_Check)
PYBIND11_OBJECT_CVT(list, object, PyList_Check, PySequence_List)
explicit list(size_t size = 0) : object(PyList_New((ssize_t) size), false) {
if (!m_ptr) pybind11_fail("Could not allocate list object!");
}
@ -736,7 +754,7 @@ class kwargs : public dict { PYBIND11_OBJECT_DEFAULT(kwargs, dict, PyDict_Check)
class set : public object {
public:
PYBIND11_OBJECT(set, object, PySet_Check)
PYBIND11_OBJECT_CVT(set, object, PySet_Check, PySet_New)
set() : object(PySet_New(nullptr), false) {
if (!m_ptr) pybind11_fail("Could not allocate set object!");
}
@ -797,7 +815,7 @@ public:
pybind11_fail("Unable to create memoryview from buffer descriptor");
}
PYBIND11_OBJECT_DEFAULT(memoryview, object, PyMemoryView_Check)
PYBIND11_OBJECT_CVT(memoryview, object, PyMemoryView_Check, PyMemoryView_FromObject)
};
inline size_t len(handle h) {
@ -807,6 +825,17 @@ inline size_t len(handle h) {
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 {str_value, false};
}
NAMESPACE_BEGIN(detail)
template <typename D> iterator object_api<D>::begin() const { return {PyObject_GetIter(derived().ptr()), false}; }
template <typename D> iterator object_api<D>::end() const { return {nullptr, false}; }
@ -820,24 +849,7 @@ template <typename D> template <typename T> bool object_api<D>::contains(T &&key
}
template <typename D>
pybind11::str object_api<D>::str() const {
PyObject *str_value = PyObject_Str(derived().ptr());
#if PY_MAJOR_VERSION < 3
PyObject *unicode = PyUnicode_FromEncodedObject(str_value, "utf-8", nullptr);
Py_XDECREF(str_value); str_value = unicode;
#endif
return {str_value, false};
}
template <typename D>
pybind11::str object_api<D>::repr() const {
PyObject *str_value = PyObject_Repr(derived().ptr());
#if PY_MAJOR_VERSION < 3
PyObject *unicode = PyUnicode_FromEncodedObject(str_value, "utf-8", nullptr);
Py_XDECREF(str_value); str_value = unicode;
#endif
return {str_value, false};
}
pybind11::str object_api<D>::str() const { return pybind11::str(derived()); }
template <typename D>
handle object_api<D>::get_type() const { return (PyObject *) Py_TYPE(derived().ptr()); }

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@ -248,7 +248,7 @@ template<> struct type_caster<std::experimental::nullopt_t>
NAMESPACE_END(detail)
inline std::ostream &operator<<(std::ostream &os, const handle &obj) {
os << (std::string) obj.str();
os << (std::string) str(obj);
return os;
}

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@ -196,14 +196,14 @@ py::list print_format_descriptors() {
py::list print_dtypes() {
const auto dtypes = {
py::dtype::of<SimpleStruct>().str(),
py::dtype::of<PackedStruct>().str(),
py::dtype::of<NestedStruct>().str(),
py::dtype::of<PartialStruct>().str(),
py::dtype::of<PartialNestedStruct>().str(),
py::dtype::of<StringStruct>().str(),
py::dtype::of<EnumStruct>().str(),
py::dtype::of<StructWithUglyNames>().str()
py::str(py::dtype::of<SimpleStruct>()),
py::str(py::dtype::of<PackedStruct>()),
py::str(py::dtype::of<NestedStruct>()),
py::str(py::dtype::of<PartialStruct>()),
py::str(py::dtype::of<PartialNestedStruct>()),
py::str(py::dtype::of<StringStruct>()),
py::str(py::dtype::of<EnumStruct>()),
py::str(py::dtype::of<StructWithUglyNames>())
};
auto l = py::list();
for (const auto &s : dtypes) {

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@ -153,8 +153,8 @@ public:
}
void test_print(const py::object& obj) {
py::print(obj.str());
py::print(obj.repr());
py::print(py::str(obj));
py::print(py::repr(obj));
}
static int value;
@ -321,4 +321,46 @@ test_initializer python_types([](py::module &m) {
m.attr("has_optional") = py::cast(has_optional);
m.attr("has_exp_optional") = py::cast(has_exp_optional);
m.def("test_default_constructors", []() {
return py::dict(
"str"_a=py::str(),
"bool"_a=py::bool_(),
"int"_a=py::int_(),
"float"_a=py::float_(),
"tuple"_a=py::tuple(),
"list"_a=py::list(),
"dict"_a=py::dict(),
"set"_a=py::set()
);
});
m.def("test_converting_constructors", [](py::dict d) {
return py::dict(
"str"_a=py::str(d["str"]),
"bool"_a=py::bool_(d["bool"]),
"int"_a=py::int_(d["int"]),
"float"_a=py::float_(d["float"]),
"tuple"_a=py::tuple(d["tuple"]),
"list"_a=py::list(d["list"]),
"dict"_a=py::dict(d["dict"]),
"set"_a=py::set(d["set"]),
"memoryview"_a=py::memoryview(d["memoryview"])
);
});
m.def("test_cast_functions", [](py::dict d) {
// When converting between Python types, obj.cast<T>() should be the same as T(obj)
return py::dict(
"str"_a=d["str"].cast<py::str>(),
"bool"_a=d["bool"].cast<py::bool_>(),
"int"_a=d["int"].cast<py::int_>(),
"float"_a=d["float"].cast<py::float_>(),
"tuple"_a=d["tuple"].cast<py::tuple>(),
"list"_a=d["list"].cast<py::list>(),
"dict"_a=d["dict"].cast<py::dict>(),
"set"_a=d["set"].cast<py::set>(),
"memoryview"_a=d["memoryview"].cast<py::memoryview>()
);
});
});

View File

@ -330,3 +330,29 @@ def test_exp_optional():
assert test_nullopt_exp(None) == 42
assert test_nullopt_exp(42) == 42
assert test_nullopt_exp(43) == 43
def test_constructors():
"""C++ default and converting constructors are equivalent to type calls in Python"""
from pybind11_tests import (test_default_constructors, test_converting_constructors,
test_cast_functions)
types = [str, bool, int, float, tuple, list, dict, set]
expected = {t.__name__: t() for t in types}
assert test_default_constructors() == expected
data = {
str: 42,
bool: "Not empty",
int: "42",
float: "+1e3",
tuple: range(3),
list: range(3),
dict: [("two", 2), ("one", 1), ("three", 3)],
set: [4, 4, 5, 6, 6, 6],
memoryview: b'abc'
}
inputs = {k.__name__: v for k, v in data.items()}
expected = {k.__name__: k(v) for k, v in data.items()}
assert test_converting_constructors(inputs) == expected
assert test_cast_functions(inputs) == expected