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/*
pybind11/stl.h: Transparent conversion for STL data 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 "pybind11.h"
#include "detail/common.h"
#include <deque>
#include <list>
#include <map>
#include <ostream>
#include <set>
#include <unordered_map>
#include <unordered_set>
#include <valarray>
// See `detail/common.h` for implementation of these guards.
#if defined(PYBIND11_HAS_OPTIONAL)
# include <optional>
#elif defined(PYBIND11_HAS_EXP_OPTIONAL)
# include <experimental/optional>
#endif
#if defined(PYBIND11_HAS_VARIANT)
# include <variant>
#endif
PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
PYBIND11_NAMESPACE_BEGIN(detail)
/// Extracts an const lvalue reference or rvalue reference for U based on the type of T (e.g. for
/// forwarding a container element). Typically used indirect via forwarded_type(), below.
template <typename T, typename U>
using forwarded_type = conditional_t<std::is_lvalue_reference<T>::value,
remove_reference_t<U> &,
remove_reference_t<U> &&>;
/// Forwards a value U as rvalue or lvalue according to whether T is rvalue or lvalue; typically
/// used for forwarding a container's elements.
template <typename T, typename U>
constexpr forwarded_type<T, U> forward_like(U &&u) {
return std::forward<detail::forwarded_type<T, U>>(std::forward<U>(u));
}
// Checks if a container has a STL style reserve method.
// This will only return true for a `reserve()` with a `void` return.
template <typename C>
using has_reserve_method = std::is_same<decltype(std::declval<C>().reserve(0)), void>;
template <typename Type, typename Key>
struct set_caster {
using type = Type;
using key_conv = make_caster<Key>;
private:
template <typename T = Type, enable_if_t<has_reserve_method<T>::value, int> = 0>
void reserve_maybe(const anyset &s, Type *) {
value.reserve(s.size());
}
void reserve_maybe(const anyset &, void *) {}
public:
bool load(handle src, bool convert) {
if (!isinstance<anyset>(src)) {
return false;
}
auto s = reinterpret_borrow<anyset>(src);
value.clear();
reserve_maybe(s, &value);
for (auto entry : s) {
key_conv conv;
if (!conv.load(entry, convert)) {
return false;
}
value.insert(cast_op<Key &&>(std::move(conv)));
}
return true;
}
template <typename T>
static handle cast(T &&src, return_value_policy policy, handle parent) {
if (!std::is_lvalue_reference<T>::value) {
policy = return_value_policy_override<Key>::policy(policy);
}
pybind11::set s;
for (auto &&value : src) {
auto value_ = reinterpret_steal<object>(
key_conv::cast(detail::forward_like<T>(value), policy, parent));
if (!value_ || !s.add(std::move(value_))) {
return handle();
}
}
return s.release();
}
PYBIND11_TYPE_CASTER(type, const_name("set[") + key_conv::name + const_name("]"));
};
template <typename Type, typename Key, typename Value>
struct map_caster {
using key_conv = make_caster<Key>;
using value_conv = make_caster<Value>;
private:
template <typename T = Type, enable_if_t<has_reserve_method<T>::value, int> = 0>
void reserve_maybe(const dict &d, Type *) {
value.reserve(d.size());
}
void reserve_maybe(const dict &, void *) {}
public:
bool load(handle src, bool convert) {
if (!isinstance<dict>(src)) {
return false;
}
auto d = reinterpret_borrow<dict>(src);
value.clear();
reserve_maybe(d, &value);
for (auto it : d) {
key_conv kconv;
value_conv vconv;
if (!kconv.load(it.first.ptr(), convert) || !vconv.load(it.second.ptr(), convert)) {
return false;
}
value.emplace(cast_op<Key &&>(std::move(kconv)), cast_op<Value &&>(std::move(vconv)));
}
return true;
}
template <typename T>
static handle cast(T &&src, return_value_policy policy, handle parent) {
dict d;
return_value_policy policy_key = policy;
return_value_policy policy_value = policy;
if (!std::is_lvalue_reference<T>::value) {
policy_key = return_value_policy_override<Key>::policy(policy_key);
policy_value = return_value_policy_override<Value>::policy(policy_value);
}
for (auto &&kv : src) {
auto key = reinterpret_steal<object>(
key_conv::cast(detail::forward_like<T>(kv.first), policy_key, parent));
auto value = reinterpret_steal<object>(
value_conv::cast(detail::forward_like<T>(kv.second), policy_value, parent));
if (!key || !value) {
return handle();
}
d[std::move(key)] = std::move(value);
}
return d.release();
}
PYBIND11_TYPE_CASTER(Type,
const_name("dict[") + key_conv::name + const_name(", ") + value_conv::name
+ const_name("]"));
};
template <typename Type, typename Value>
struct list_caster {
using value_conv = make_caster<Value>;
bool load(handle src, bool convert) {
if (!isinstance<sequence>(src) || isinstance<bytes>(src) || isinstance<str>(src)) {
return false;
}
auto s = reinterpret_borrow<sequence>(src);
value.clear();
reserve_maybe(s, &value);
for (const auto &it : s) {
value_conv conv;
if (!conv.load(it, convert)) {
return false;
}
value.push_back(cast_op<Value &&>(std::move(conv)));
}
return true;
}
private:
template <typename T = Type, enable_if_t<has_reserve_method<T>::value, int> = 0>
void reserve_maybe(const sequence &s, Type *) {
value.reserve(s.size());
}
void reserve_maybe(const sequence &, void *) {}
public:
template <typename T>
static handle cast(T &&src, return_value_policy policy, handle parent) {
if (!std::is_lvalue_reference<T>::value) {
policy = return_value_policy_override<Value>::policy(policy);
}
list l(src.size());
ssize_t index = 0;
for (auto &&value : src) {
auto value_ = reinterpret_steal<object>(
value_conv::cast(detail::forward_like<T>(value), policy, parent));
if (!value_) {
return handle();
}
PyList_SET_ITEM(l.ptr(), index++, value_.release().ptr()); // steals a reference
}
return l.release();
}
PYBIND11_TYPE_CASTER(Type, const_name("list[") + value_conv::name + const_name("]"));
};
template <typename Type, typename Alloc>
struct type_caster<std::vector<Type, Alloc>> : list_caster<std::vector<Type, Alloc>, Type> {};
template <typename Type, typename Alloc>
struct type_caster<std::deque<Type, Alloc>> : list_caster<std::deque<Type, Alloc>, Type> {};
template <typename Type, typename Alloc>
struct type_caster<std::list<Type, Alloc>> : list_caster<std::list<Type, Alloc>, Type> {};
template <typename ArrayType, typename Value, bool Resizable, size_t Size = 0>
struct array_caster {
using value_conv = make_caster<Value>;
private:
template <bool R = Resizable>
bool require_size(enable_if_t<R, size_t> size) {
if (value.size() != size) {
value.resize(size);
}
return true;
}
template <bool R = Resizable>
bool require_size(enable_if_t<!R, size_t> size) {
return size == Size;
}
public:
bool load(handle src, bool convert) {
if (!isinstance<sequence>(src)) {
return false;
}
auto l = reinterpret_borrow<sequence>(src);
if (!require_size(l.size())) {
return false;
}
size_t ctr = 0;
for (const auto &it : l) {
value_conv conv;
if (!conv.load(it, convert)) {
return false;
}
value[ctr++] = cast_op<Value &&>(std::move(conv));
}
return true;
}
template <typename T>
static handle cast(T &&src, return_value_policy policy, handle parent) {
list l(src.size());
ssize_t index = 0;
for (auto &&value : src) {
auto value_ = reinterpret_steal<object>(
value_conv::cast(detail::forward_like<T>(value), policy, parent));
if (!value_) {
return handle();
}
PyList_SET_ITEM(l.ptr(), index++, value_.release().ptr()); // steals a reference
}
return l.release();
}
PYBIND11_TYPE_CASTER(ArrayType,
const_name<Resizable>(const_name(""), const_name("Annotated["))
+ const_name("list[") + value_conv::name + const_name("]")
+ const_name<Resizable>(const_name(""),
const_name(", FixedSize(")
+ const_name<Size>() + const_name(")]")));
};
template <typename Type, size_t Size>
struct type_caster<std::array<Type, Size>>
: array_caster<std::array<Type, Size>, Type, false, Size> {};
template <typename Type>
struct type_caster<std::valarray<Type>> : array_caster<std::valarray<Type>, Type, true> {};
template <typename Key, typename Compare, typename Alloc>
struct type_caster<std::set<Key, Compare, Alloc>>
: set_caster<std::set<Key, Compare, Alloc>, Key> {};
template <typename Key, typename Hash, typename Equal, typename Alloc>
struct type_caster<std::unordered_set<Key, Hash, Equal, Alloc>>
: set_caster<std::unordered_set<Key, Hash, Equal, Alloc>, Key> {};
template <typename Key, typename Value, typename Compare, typename Alloc>
struct type_caster<std::map<Key, Value, Compare, Alloc>>
: map_caster<std::map<Key, Value, Compare, Alloc>, Key, Value> {};
template <typename Key, typename Value, typename Hash, typename Equal, typename Alloc>
struct type_caster<std::unordered_map<Key, Value, Hash, Equal, Alloc>>
: map_caster<std::unordered_map<Key, Value, Hash, Equal, Alloc>, Key, Value> {};
// This type caster is intended to be used for std::optional and std::experimental::optional
template <typename Type, typename Value = typename Type::value_type>
struct optional_caster {
using value_conv = make_caster<Value>;
template <typename T>
static handle cast(T &&src, return_value_policy policy, handle parent) {
if (!src) {
return none().release();
}
if (!std::is_lvalue_reference<T>::value) {
policy = return_value_policy_override<Value>::policy(policy);
}
// NOLINTNEXTLINE(bugprone-unchecked-optional-access)
return value_conv::cast(*std::forward<T>(src), policy, parent);
}
bool load(handle src, bool convert) {
if (!src) {
return false;
}
if (src.is_none()) {
return true; // default-constructed value is already empty
}
value_conv inner_caster;
if (!inner_caster.load(src, convert)) {
return false;
}
value.emplace(cast_op<Value &&>(std::move(inner_caster)));
return true;
}
PYBIND11_TYPE_CASTER(Type, const_name("Optional[") + value_conv::name + const_name("]"));
};
#if defined(PYBIND11_HAS_OPTIONAL)
template <typename T>
struct type_caster<std::optional<T>> : public optional_caster<std::optional<T>> {};
template <>
struct type_caster<std::nullopt_t> : public void_caster<std::nullopt_t> {};
#endif
#if defined(PYBIND11_HAS_EXP_OPTIONAL)
template <typename T>
struct type_caster<std::experimental::optional<T>>
: public optional_caster<std::experimental::optional<T>> {};
template <>
struct type_caster<std::experimental::nullopt_t>
: public void_caster<std::experimental::nullopt_t> {};
#endif
/// Visit a variant and cast any found type to Python
struct variant_caster_visitor {
return_value_policy policy;
handle parent;
using result_type = handle; // required by boost::variant in C++11
template <typename T>
result_type operator()(T &&src) const {
return make_caster<T>::cast(std::forward<T>(src), policy, parent);
}
};
/// Helper class which abstracts away variant's `visit` function. `std::variant` and similar
/// `namespace::variant` types which provide a `namespace::visit()` function are handled here
/// automatically using argument-dependent lookup. Users can provide specializations for other
/// variant-like classes, e.g. `boost::variant` and `boost::apply_visitor`.
template <template <typename...> class Variant>
struct visit_helper {
template <typename... Args>
static auto call(Args &&...args) -> decltype(visit(std::forward<Args>(args)...)) {
return visit(std::forward<Args>(args)...);
}
};
/// Generic variant caster
template <typename Variant>
struct variant_caster;
template <template <typename...> class V, typename... Ts>
struct variant_caster<V<Ts...>> {
static_assert(sizeof...(Ts) > 0, "Variant must consist of at least one alternative.");
template <typename U, typename... Us>
bool load_alternative(handle src, bool convert, type_list<U, Us...>) {
auto caster = make_caster<U>();
if (caster.load(src, convert)) {
value = cast_op<U>(std::move(caster));
return true;
}
return load_alternative(src, convert, type_list<Us...>{});
}
bool load_alternative(handle, bool, type_list<>) { return false; }
bool load(handle src, bool convert) {
// Do a first pass without conversions to improve constructor resolution.
// E.g. `py::int_(1).cast<variant<double, int>>()` needs to fill the `int`
// slot of the variant. Without two-pass loading `double` would be filled
// because it appears first and a conversion is possible.
if (convert && load_alternative(src, false, type_list<Ts...>{})) {
return true;
}
return load_alternative(src, convert, type_list<Ts...>{});
}
template <typename Variant>
static handle cast(Variant &&src, return_value_policy policy, handle parent) {
return visit_helper<V>::call(variant_caster_visitor{policy, parent},
std::forward<Variant>(src));
}
using Type = V<Ts...>;
PYBIND11_TYPE_CASTER(Type,
const_name("Union[")
+ ::pybind11::detail::concat(make_caster<Ts>::name...)
+ const_name("]"));
};
#if defined(PYBIND11_HAS_VARIANT)
template <typename... Ts>
struct type_caster<std::variant<Ts...>> : variant_caster<std::variant<Ts...>> {};
template <>
struct type_caster<std::monostate> : public void_caster<std::monostate> {};
#endif
PYBIND11_NAMESPACE_END(detail)
inline std::ostream &operator<<(std::ostream &os, const handle &obj) {
#ifdef PYBIND11_HAS_STRING_VIEW
os << str(obj).cast<std::string_view>();
#else
os << (std::string) str(obj);
#endif
return os;
}
PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)