cppast/include/cppast/cpp_entity_ref.hpp
2017-04-12 18:19:08 +02:00

131 lines
4.5 KiB
C++

// Copyright (C) 2017 Jonathan Müller <jonathanmueller.dev@gmail.com>
// This file is subject to the license terms in the LICENSE file
// found in the top-level directory of this distribution.
#ifndef CPPAST_CPP_ENTITY_REF_HPP_INCLUDED
#define CPPAST_CPP_ENTITY_REF_HPP_INCLUDED
#include <vector>
#include <type_safe/variant.hpp>
#include <cppast/detail/assert.hpp>
#include <cppast/cpp_entity_index.hpp>
namespace cppast
{
enum class cpp_entity_kind;
/// A basic reference to some kind of [cppast::cpp_entity]().
///
/// It can either refer to a single [cppast::cpp_entity]()
/// or multiple.
/// In the later case it is *overloaded*.
template <typename T, typename Predicate>
class basic_cpp_entity_ref
{
public:
/// \effects Creates it giving it the target id and name.
basic_cpp_entity_ref(cpp_entity_id target_id, std::string target_name)
: target_(std::move(target_id)), name_(std::move(target_name))
{
}
/// \effects Creates it giving it multiple target ids and name.
/// \notes This is to refer to an overloaded function.
basic_cpp_entity_ref(std::vector<cpp_entity_id> target_ids, std::string target_name)
: target_(std::move(target_ids)), name_(std::move(target_name))
{
}
/// \returns The name of the reference, as spelled in the source code.
const std::string& name() const noexcept
{
return name_;
}
/// \returns Whether or not it refers to multiple entities.
bool is_overloaded() const noexcept
{
return target_.has_value(type_safe::variant_type<std::vector<cpp_entity_id>>{});
}
/// \returns The number of entities it refers to.
type_safe::size_t no_overloaded() const noexcept
{
return id().size();
}
/// \returns An array reference to the id or ids it refers to.
type_safe::array_ref<const cpp_entity_id> id() const noexcept
{
if (is_overloaded())
{
auto& vec = target_.value(type_safe::variant_type<std::vector<cpp_entity_id>>{});
return type_safe::ref(vec.data(), vec.size());
}
else
{
auto& id = target_.value(type_safe::variant_type<cpp_entity_id>{});
return type_safe::ref(&id, 1u);
}
}
/// \returns An array reference to the entities it refers to.
/// The return type provides `operator[]` + `size()`,
/// as well as `begin()` and `end()` returning forward iterators.
/// \exclude return
std::vector<type_safe::object_ref<const T>> get(const cpp_entity_index& idx) const
{
std::vector<type_safe::object_ref<const T>> result;
get_impl(std::is_convertible<cpp_namespace&, T&>{}, result, idx);
return result;
}
private:
void get_impl(std::true_type, std::vector<type_safe::object_ref<const T>>& result,
const cpp_entity_index& idx) const
{
for (auto& cur : id())
for (auto& ns : idx.lookup_namespace(cur))
result.push_back(ns);
if (!std::is_same<T, cpp_namespace>::value)
get_impl(std::false_type{}, result, idx);
}
void get_impl(std::false_type, std::vector<type_safe::object_ref<const T>>& result,
const cpp_entity_index& idx) const
{
for (auto& cur : id())
{
auto entity = idx.lookup(cur).map([](const cpp_entity& e) {
DEBUG_ASSERT(Predicate{}(e), detail::precondition_error_handler{},
"invalid entity type");
return type_safe::ref(static_cast<const T&>(e));
});
if (entity)
result.push_back(type_safe::ref(entity.value()));
}
}
type_safe::variant<cpp_entity_id, std::vector<cpp_entity_id>> target_;
std::string name_;
};
/// \exclude
namespace detail
{
struct cpp_entity_ref_predicate
{
bool operator()(const cpp_entity&)
{
return true;
}
};
}
/// A [cppast::basic_cpp_entity_ref]() to any [cppast::cpp_entity]().
using cpp_entity_ref = basic_cpp_entity_ref<cpp_entity, detail::cpp_entity_ref_predicate>;
} // namespace cppast
#endif // CPPAST_CPP_ENTITY_REF_HPP_INCLUDED