File indexing completed on 2025-02-16 05:12:19

 /*
     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 "detail/common.h"
 #include "pybind11.h"
 #include <set>
 #include <unordered_set>
 #include <map>
 #include <unordered_map>
 #include <iostream>
 #include <list>
 #include <deque>
 #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>
 forwarded_type<T, U> forward_like(U &&u) {
     return std::forward<detail::forwarded_type<T, U>>(std::forward<U>(u));
 }
 
 template <typename Type, typename Key> struct set_caster {
     using type = Type;
     using key_conv = make_caster<Key>;
 
     bool load(handle src, bool convert) {
         if (!isinstance<pybind11::set>(src))
             return false;
         auto s = reinterpret_borrow<pybind11::set>(src);
         value.clear();
         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(forward_like<T>(value), policy, parent));
             if (!value_ || !s.add(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>;
 
     bool load(handle src, bool convert) {
         if (!isinstance<dict>(src))
             return false;
         auto d = reinterpret_borrow<dict>(src);
         value.clear();
         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(forward_like<T>(kv.first), policy_key, parent));
             auto value = reinterpret_steal<object>(value_conv::cast(forward_like<T>(kv.second), policy_value, parent));
             if (!key || !value)
                 return handle();
             d[key] = 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 (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<std::is_same<decltype(std::declval<T>().reserve(0)), void>::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(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 (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(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("List[") + value_conv::name + const_name<Resizable>(const_name(""), const_name("[") + const_name<Size>() + const_name("]")) + 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().inc_ref();
         if (!std::is_lvalue_reference<T>::value) {
             policy = return_value_policy_override<Value>::policy(policy);
         }
         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>(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[") + 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...>> { };
 #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)