blob: 050be83cc591f45b8697bc0589e9427a6c6fe48b [file] [log] [blame]
/*
pybind11/std_bind.h: Binding generators for STL data types
Copyright (c) 2016 Sergey Lyskov and Wenzel Jakob
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 "operators.h"
#include <algorithm>
#include <sstream>
PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
PYBIND11_NAMESPACE_BEGIN(detail)
/* SFINAE helper class used by 'is_comparable */
template <typename T> struct container_traits {
template <typename T2> static std::true_type test_comparable(decltype(std::declval<const T2 &>() == std::declval<const T2 &>())*);
template <typename T2> static std::false_type test_comparable(...);
template <typename T2> static std::true_type test_value(typename T2::value_type *);
template <typename T2> static std::false_type test_value(...);
template <typename T2> static std::true_type test_pair(typename T2::first_type *, typename T2::second_type *);
template <typename T2> static std::false_type test_pair(...);
static constexpr const bool is_comparable = std::is_same<std::true_type, decltype(test_comparable<T>(nullptr))>::value;
static constexpr const bool is_pair = std::is_same<std::true_type, decltype(test_pair<T>(nullptr, nullptr))>::value;
static constexpr const bool is_vector = std::is_same<std::true_type, decltype(test_value<T>(nullptr))>::value;
static constexpr const bool is_element = !is_pair && !is_vector;
};
/* Default: is_comparable -> std::false_type */
template <typename T, typename SFINAE = void>
struct is_comparable : std::false_type { };
/* For non-map data structures, check whether operator== can be instantiated */
template <typename T>
struct is_comparable<
T, enable_if_t<container_traits<T>::is_element &&
container_traits<T>::is_comparable>>
: std::true_type { };
/* For a vector/map data structure, recursively check the value type (which is std::pair for maps) */
template <typename T>
struct is_comparable<T, enable_if_t<container_traits<T>::is_vector>> {
static constexpr const bool value =
is_comparable<typename T::value_type>::value;
};
/* For pairs, recursively check the two data types */
template <typename T>
struct is_comparable<T, enable_if_t<container_traits<T>::is_pair>> {
static constexpr const bool value =
is_comparable<typename T::first_type>::value &&
is_comparable<typename T::second_type>::value;
};
/* Fallback functions */
template <typename, typename, typename... Args> void vector_if_copy_constructible(const Args &...) { }
template <typename, typename, typename... Args> void vector_if_equal_operator(const Args &...) { }
template <typename, typename, typename... Args> void vector_if_insertion_operator(const Args &...) { }
template <typename, typename, typename... Args> void vector_modifiers(const Args &...) { }
template<typename Vector, typename Class_>
void vector_if_copy_constructible(enable_if_t<is_copy_constructible<Vector>::value, Class_> &cl) {
cl.def(init<const Vector &>(), "Copy constructor");
}
template<typename Vector, typename Class_>
void vector_if_equal_operator(enable_if_t<is_comparable<Vector>::value, Class_> &cl) {
using T = typename Vector::value_type;
cl.def(self == self);
cl.def(self != self);
cl.def("count",
[](const Vector &v, const T &x) {
return std::count(v.begin(), v.end(), x);
},
arg("x"),
"Return the number of times ``x`` appears in the list"
);
cl.def("remove", [](Vector &v, const T &x) {
auto p = std::find(v.begin(), v.end(), x);
if (p != v.end())
v.erase(p);
else
throw value_error();
},
arg("x"),
"Remove the first item from the list whose value is x. "
"It is an error if there is no such item."
);
cl.def("__contains__",
[](const Vector &v, const T &x) {
return std::find(v.begin(), v.end(), x) != v.end();
},
arg("x"),
"Return true the container contains ``x``"
);
}
// Vector modifiers -- requires a copyable vector_type:
// (Technically, some of these (pop and __delitem__) don't actually require copyability, but it seems
// silly to allow deletion but not insertion, so include them here too.)
template <typename Vector, typename Class_>
void vector_modifiers(enable_if_t<is_copy_constructible<typename Vector::value_type>::value, Class_> &cl) {
using T = typename Vector::value_type;
using SizeType = typename Vector::size_type;
using DiffType = typename Vector::difference_type;
auto wrap_i = [](DiffType i, SizeType n) {
if (i < 0)
i += n;
if (i < 0 || (SizeType)i >= n)
throw index_error();
return i;
};
cl.def("append",
[](Vector &v, const T &value) { v.push_back(value); },
arg("x"),
"Add an item to the end of the list");
cl.def(init([](const iterable &it) {
auto v = std::unique_ptr<Vector>(new Vector());
v->reserve(len_hint(it));
for (handle h : it)
v->push_back(h.cast<T>());
return v.release();
}));
cl.def("clear",
[](Vector &v) {
v.clear();
},
"Clear the contents"
);
cl.def("extend",
[](Vector &v, const Vector &src) {
v.insert(v.end(), src.begin(), src.end());
},
arg("L"),
"Extend the list by appending all the items in the given list"
);
cl.def(
"extend",
[](Vector &v, const iterable &it) {
const size_t old_size = v.size();
v.reserve(old_size + len_hint(it));
try {
for (handle h : it) {
v.push_back(h.cast<T>());
}
} catch (const cast_error &) {
v.erase(v.begin() + static_cast<typename Vector::difference_type>(old_size),
v.end());
try {
v.shrink_to_fit();
} catch (const std::exception &) {
// Do nothing
}
throw;
}
},
arg("L"),
"Extend the list by appending all the items in the given list");
cl.def("insert",
[](Vector &v, DiffType i, const T &x) {
// Can't use wrap_i; i == v.size() is OK
if (i < 0)
i += v.size();
if (i < 0 || (SizeType)i > v.size())
throw index_error();
v.insert(v.begin() + i, x);
},
arg("i") , arg("x"),
"Insert an item at a given position."
);
cl.def("pop",
[](Vector &v) {
if (v.empty())
throw index_error();
T t = std::move(v.back());
v.pop_back();
return t;
},
"Remove and return the last item"
);
cl.def("pop",
[wrap_i](Vector &v, DiffType i) {
i = wrap_i(i, v.size());
T t = std::move(v[(SizeType) i]);
v.erase(std::next(v.begin(), i));
return t;
},
arg("i"),
"Remove and return the item at index ``i``"
);
cl.def("__setitem__",
[wrap_i](Vector &v, DiffType i, const T &t) {
i = wrap_i(i, v.size());
v[(SizeType)i] = t;
}
);
/// Slicing protocol
cl.def(
"__getitem__",
[](const Vector &v, slice slice) -> Vector * {
size_t start = 0, stop = 0, step = 0, slicelength = 0;
if (!slice.compute(v.size(), &start, &stop, &step, &slicelength))
throw error_already_set();
auto *seq = new Vector();
seq->reserve((size_t) slicelength);
for (size_t i=0; i<slicelength; ++i) {
seq->push_back(v[start]);
start += step;
}
return seq;
},
arg("s"),
"Retrieve list elements using a slice object");
cl.def(
"__setitem__",
[](Vector &v, slice slice, const Vector &value) {
size_t start = 0, stop = 0, step = 0, slicelength = 0;
if (!slice.compute(v.size(), &start, &stop, &step, &slicelength))
throw error_already_set();
if (slicelength != value.size())
throw std::runtime_error("Left and right hand size of slice assignment have different sizes!");
for (size_t i=0; i<slicelength; ++i) {
v[start] = value[i];
start += step;
}
},
"Assign list elements using a slice object");
cl.def("__delitem__",
[wrap_i](Vector &v, DiffType i) {
i = wrap_i(i, v.size());
v.erase(v.begin() + i);
},
"Delete the list elements at index ``i``"
);
cl.def(
"__delitem__",
[](Vector &v, slice slice) {
size_t start = 0, stop = 0, step = 0, slicelength = 0;
if (!slice.compute(v.size(), &start, &stop, &step, &slicelength))
throw error_already_set();
if (step == 1 && false) {
v.erase(v.begin() + (DiffType) start, v.begin() + DiffType(start + slicelength));
} else {
for (size_t i = 0; i < slicelength; ++i) {
v.erase(v.begin() + DiffType(start));
start += step - 1;
}
}
},
"Delete list elements using a slice object");
}
// If the type has an operator[] that doesn't return a reference (most notably std::vector<bool>),
// we have to access by copying; otherwise we return by reference.
template <typename Vector> using vector_needs_copy = negation<
std::is_same<decltype(std::declval<Vector>()[typename Vector::size_type()]), typename Vector::value_type &>>;
// The usual case: access and iterate by reference
template <typename Vector, typename Class_>
void vector_accessor(enable_if_t<!vector_needs_copy<Vector>::value, Class_> &cl) {
using T = typename Vector::value_type;
using SizeType = typename Vector::size_type;
using DiffType = typename Vector::difference_type;
using ItType = typename Vector::iterator;
auto wrap_i = [](DiffType i, SizeType n) {
if (i < 0)
i += n;
if (i < 0 || (SizeType)i >= n)
throw index_error();
return i;
};
cl.def("__getitem__",
[wrap_i](Vector &v, DiffType i) -> T & {
i = wrap_i(i, v.size());
return v[(SizeType)i];
},
return_value_policy::reference_internal // ref + keepalive
);
cl.def("__iter__",
[](Vector &v) {
return make_iterator<
return_value_policy::reference_internal, ItType, ItType, T&>(
v.begin(), v.end());
},
keep_alive<0, 1>() /* Essential: keep list alive while iterator exists */
);
}
// The case for special objects, like std::vector<bool>, that have to be returned-by-copy:
template <typename Vector, typename Class_>
void vector_accessor(enable_if_t<vector_needs_copy<Vector>::value, Class_> &cl) {
using T = typename Vector::value_type;
using SizeType = typename Vector::size_type;
using DiffType = typename Vector::difference_type;
using ItType = typename Vector::iterator;
cl.def("__getitem__",
[](const Vector &v, DiffType i) -> T {
if (i < 0 && (i += v.size()) < 0)
throw index_error();
if ((SizeType)i >= v.size())
throw index_error();
return v[(SizeType)i];
}
);
cl.def("__iter__",
[](Vector &v) {
return make_iterator<
return_value_policy::copy, ItType, ItType, T>(
v.begin(), v.end());
},
keep_alive<0, 1>() /* Essential: keep list alive while iterator exists */
);
}
template <typename Vector, typename Class_> auto vector_if_insertion_operator(Class_ &cl, std::string const &name)
-> decltype(std::declval<std::ostream&>() << std::declval<typename Vector::value_type>(), void()) {
using size_type = typename Vector::size_type;
cl.def("__repr__",
[name](Vector &v) {
std::ostringstream s;
s << name << '[';
for (size_type i=0; i < v.size(); ++i) {
s << v[i];
if (i != v.size() - 1)
s << ", ";
}
s << ']';
return s.str();
},
"Return the canonical string representation of this list."
);
}
// Provide the buffer interface for vectors if we have data() and we have a format for it
// GCC seems to have "void std::vector<bool>::data()" - doing SFINAE on the existence of data() is insufficient, we need to check it returns an appropriate pointer
template <typename Vector, typename = void>
struct vector_has_data_and_format : std::false_type {};
template <typename Vector>
struct vector_has_data_and_format<Vector, enable_if_t<std::is_same<decltype(format_descriptor<typename Vector::value_type>::format(), std::declval<Vector>().data()), typename Vector::value_type*>::value>> : std::true_type {};
// [workaround(intel)] Separate function required here
// Workaround as the Intel compiler does not compile the enable_if_t part below
// (tested with icc (ICC) 2021.1 Beta 20200827)
template <typename... Args>
constexpr bool args_any_are_buffer() {
return detail::any_of<std::is_same<Args, buffer_protocol>...>::value;
}
// [workaround(intel)] Separate function required here
// [workaround(msvc)] Can't use constexpr bool in return type
// Add the buffer interface to a vector
template <typename Vector, typename Class_, typename... Args>
void vector_buffer_impl(Class_& cl, std::true_type) {
using T = typename Vector::value_type;
static_assert(vector_has_data_and_format<Vector>::value, "There is not an appropriate format descriptor for this vector");
// numpy.h declares this for arbitrary types, but it may raise an exception and crash hard at runtime if PYBIND11_NUMPY_DTYPE hasn't been called, so check here
format_descriptor<T>::format();
cl.def_buffer([](Vector& v) -> buffer_info {
return buffer_info(v.data(), static_cast<ssize_t>(sizeof(T)), format_descriptor<T>::format(), 1, {v.size()}, {sizeof(T)});
});
cl.def(init([](const buffer &buf) {
auto info = buf.request();
if (info.ndim != 1 || info.strides[0] % static_cast<ssize_t>(sizeof(T)))
throw type_error("Only valid 1D buffers can be copied to a vector");
if (!detail::compare_buffer_info<T>::compare(info) || (ssize_t) sizeof(T) != info.itemsize)
throw type_error("Format mismatch (Python: " + info.format + " C++: " + format_descriptor<T>::format() + ")");
T *p = static_cast<T*>(info.ptr);
ssize_t step = info.strides[0] / static_cast<ssize_t>(sizeof(T));
T *end = p + info.shape[0] * step;
if (step == 1) {
return Vector(p, end);
}
Vector vec;
vec.reserve((size_t) info.shape[0]);
for (; p != end; p += step)
vec.push_back(*p);
return vec;
}));
return;
}
template <typename Vector, typename Class_, typename... Args>
void vector_buffer_impl(Class_&, std::false_type) {}
template <typename Vector, typename Class_, typename... Args>
void vector_buffer(Class_& cl) {
vector_buffer_impl<Vector, Class_, Args...>(cl, detail::any_of<std::is_same<Args, buffer_protocol>...>{});
}
PYBIND11_NAMESPACE_END(detail)
//
// std::vector
//
template <typename Vector, typename holder_type = std::unique_ptr<Vector>, typename... Args>
class_<Vector, holder_type> bind_vector(handle scope, std::string const &name, Args&&... args) {
using Class_ = class_<Vector, holder_type>;
// If the value_type is unregistered (e.g. a converting type) or is itself registered
// module-local then make the vector binding module-local as well:
using vtype = typename Vector::value_type;
auto vtype_info = detail::get_type_info(typeid(vtype));
bool local = !vtype_info || vtype_info->module_local;
Class_ cl(scope, name.c_str(), pybind11::module_local(local), std::forward<Args>(args)...);
// Declare the buffer interface if a buffer_protocol() is passed in
detail::vector_buffer<Vector, Class_, Args...>(cl);
cl.def(init<>());
// Register copy constructor (if possible)
detail::vector_if_copy_constructible<Vector, Class_>(cl);
// Register comparison-related operators and functions (if possible)
detail::vector_if_equal_operator<Vector, Class_>(cl);
// Register stream insertion operator (if possible)
detail::vector_if_insertion_operator<Vector, Class_>(cl, name);
// Modifiers require copyable vector value type
detail::vector_modifiers<Vector, Class_>(cl);
// Accessor and iterator; return by value if copyable, otherwise we return by ref + keep-alive
detail::vector_accessor<Vector, Class_>(cl);
cl.def("__bool__",
[](const Vector &v) -> bool {
return !v.empty();
},
"Check whether the list is nonempty"
);
cl.def("__len__", &Vector::size);
#if 0
// C++ style functions deprecated, leaving it here as an example
cl.def(init<size_type>());
cl.def("resize",
(void (Vector::*) (size_type count)) & Vector::resize,
"changes the number of elements stored");
cl.def("erase",
[](Vector &v, SizeType i) {
if (i >= v.size())
throw index_error();
v.erase(v.begin() + i);
}, "erases element at index ``i``");
cl.def("empty", &Vector::empty, "checks whether the container is empty");
cl.def("size", &Vector::size, "returns the number of elements");
cl.def("push_back", (void (Vector::*)(const T&)) &Vector::push_back, "adds an element to the end");
cl.def("pop_back", &Vector::pop_back, "removes the last element");
cl.def("max_size", &Vector::max_size, "returns the maximum possible number of elements");
cl.def("reserve", &Vector::reserve, "reserves storage");
cl.def("capacity", &Vector::capacity, "returns the number of elements that can be held in currently allocated storage");
cl.def("shrink_to_fit", &Vector::shrink_to_fit, "reduces memory usage by freeing unused memory");
cl.def("clear", &Vector::clear, "clears the contents");
cl.def("swap", &Vector::swap, "swaps the contents");
cl.def("front", [](Vector &v) {
if (v.size()) return v.front();
else throw index_error();
}, "access the first element");
cl.def("back", [](Vector &v) {
if (v.size()) return v.back();
else throw index_error();
}, "access the last element ");
#endif
return cl;
}
//
// std::map, std::unordered_map
//
PYBIND11_NAMESPACE_BEGIN(detail)
/* Fallback functions */
template <typename, typename, typename... Args> void map_if_insertion_operator(const Args &...) { }
template <typename, typename, typename... Args> void map_assignment(const Args &...) { }
// Map assignment when copy-assignable: just copy the value
template <typename Map, typename Class_>
void map_assignment(enable_if_t<is_copy_assignable<typename Map::mapped_type>::value, Class_> &cl) {
using KeyType = typename Map::key_type;
using MappedType = typename Map::mapped_type;
cl.def("__setitem__",
[](Map &m, const KeyType &k, const MappedType &v) {
auto it = m.find(k);
if (it != m.end()) it->second = v;
else m.emplace(k, v);
}
);
}
// Not copy-assignable, but still copy-constructible: we can update the value by erasing and reinserting
template<typename Map, typename Class_>
void map_assignment(enable_if_t<
!is_copy_assignable<typename Map::mapped_type>::value &&
is_copy_constructible<typename Map::mapped_type>::value,
Class_> &cl) {
using KeyType = typename Map::key_type;
using MappedType = typename Map::mapped_type;
cl.def("__setitem__",
[](Map &m, const KeyType &k, const MappedType &v) {
// We can't use m[k] = v; because value type might not be default constructable
auto r = m.emplace(k, v);
if (!r.second) {
// value type is not copy assignable so the only way to insert it is to erase it first...
m.erase(r.first);
m.emplace(k, v);
}
}
);
}
template <typename Map, typename Class_> auto map_if_insertion_operator(Class_ &cl, std::string const &name)
-> decltype(std::declval<std::ostream&>() << std::declval<typename Map::key_type>() << std::declval<typename Map::mapped_type>(), void()) {
cl.def("__repr__",
[name](Map &m) {
std::ostringstream s;
s << name << '{';
bool f = false;
for (auto const &kv : m) {
if (f)
s << ", ";
s << kv.first << ": " << kv.second;
f = true;
}
s << '}';
return s.str();
},
"Return the canonical string representation of this map."
);
}
template<typename Map>
struct keys_view
{
Map &map;
};
template<typename Map>
struct values_view
{
Map &map;
};
template<typename Map>
struct items_view
{
Map &map;
};
PYBIND11_NAMESPACE_END(detail)
template <typename Map, typename holder_type = std::unique_ptr<Map>, typename... Args>
class_<Map, holder_type> bind_map(handle scope, const std::string &name, Args&&... args) {
using KeyType = typename Map::key_type;
using MappedType = typename Map::mapped_type;
using KeysView = detail::keys_view<Map>;
using ValuesView = detail::values_view<Map>;
using ItemsView = detail::items_view<Map>;
using Class_ = class_<Map, holder_type>;
// If either type is a non-module-local bound type then make the map binding non-local as well;
// otherwise (e.g. both types are either module-local or converting) the map will be
// module-local.
auto tinfo = detail::get_type_info(typeid(MappedType));
bool local = !tinfo || tinfo->module_local;
if (local) {
tinfo = detail::get_type_info(typeid(KeyType));
local = !tinfo || tinfo->module_local;
}
Class_ cl(scope, name.c_str(), pybind11::module_local(local), std::forward<Args>(args)...);
class_<KeysView> keys_view(
scope, ("KeysView[" + name + "]").c_str(), pybind11::module_local(local));
class_<ValuesView> values_view(
scope, ("ValuesView[" + name + "]").c_str(), pybind11::module_local(local));
class_<ItemsView> items_view(
scope, ("ItemsView[" + name + "]").c_str(), pybind11::module_local(local));
cl.def(init<>());
// Register stream insertion operator (if possible)
detail::map_if_insertion_operator<Map, Class_>(cl, name);
cl.def("__bool__",
[](const Map &m) -> bool { return !m.empty(); },
"Check whether the map is nonempty"
);
cl.def("__iter__",
[](Map &m) { return make_key_iterator(m.begin(), m.end()); },
keep_alive<0, 1>() /* Essential: keep map alive while iterator exists */
);
cl.def("keys",
[](Map &m) { return KeysView{m}; },
keep_alive<0, 1>() /* Essential: keep map alive while view exists */
);
cl.def("values",
[](Map &m) { return ValuesView{m}; },
keep_alive<0, 1>() /* Essential: keep map alive while view exists */
);
cl.def("items",
[](Map &m) { return ItemsView{m}; },
keep_alive<0, 1>() /* Essential: keep map alive while view exists */
);
cl.def("__getitem__",
[](Map &m, const KeyType &k) -> MappedType & {
auto it = m.find(k);
if (it == m.end())
throw key_error();
return it->second;
},
return_value_policy::reference_internal // ref + keepalive
);
cl.def("__contains__",
[](Map &m, const KeyType &k) -> bool {
auto it = m.find(k);
if (it == m.end())
return false;
return true;
}
);
// Fallback for when the object is not of the key type
cl.def("__contains__", [](Map &, const object &) -> bool { return false; });
// Assignment provided only if the type is copyable
detail::map_assignment<Map, Class_>(cl);
cl.def("__delitem__",
[](Map &m, const KeyType &k) {
auto it = m.find(k);
if (it == m.end())
throw key_error();
m.erase(it);
}
);
cl.def("__len__", &Map::size);
keys_view.def("__len__", [](KeysView &view) { return view.map.size(); });
keys_view.def("__iter__",
[](KeysView &view) {
return make_key_iterator(view.map.begin(), view.map.end());
},
keep_alive<0, 1>() /* Essential: keep view alive while iterator exists */
);
keys_view.def("__contains__",
[](KeysView &view, const KeyType &k) -> bool {
auto it = view.map.find(k);
if (it == view.map.end())
return false;
return true;
}
);
// Fallback for when the object is not of the key type
keys_view.def("__contains__", [](KeysView &, const object &) -> bool { return false; });
values_view.def("__len__", [](ValuesView &view) { return view.map.size(); });
values_view.def("__iter__",
[](ValuesView &view) {
return make_value_iterator(view.map.begin(), view.map.end());
},
keep_alive<0, 1>() /* Essential: keep view alive while iterator exists */
);
items_view.def("__len__", [](ItemsView &view) { return view.map.size(); });
items_view.def("__iter__",
[](ItemsView &view) {
return make_iterator(view.map.begin(), view.map.end());
},
keep_alive<0, 1>() /* Essential: keep view alive while iterator exists */
);
return cl;
}
PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)