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#pragma once
#include <exception>
#include <memory>
#include <stdexcept>
namespace nix {
/* A simple non-nullable reference-counted pointer. Actually a wrapper
around std::shared_ptr that prevents non-null constructions. */
template <typename T>
class ref { // TODO(tazjin): rename to brainworm_ref or something
private:
std::shared_ptr<T> p;
public:
ref<T>(const ref<T>& r) : p(r.p) {}
explicit ref<T>(const std::shared_ptr<T>& p) : p(p) {
if (!p) {
throw std::invalid_argument("null pointer cast to ref");
}
}
explicit ref<T>(T* p) : p(p) {
if (!p) {
throw std::invalid_argument("null pointer cast to ref");
}
}
T* operator->() const { return &*p; }
T& operator*() const { return *p; }
operator std::shared_ptr<T>() const { return p; }
std::shared_ptr<T> get_ptr() const { return p; }
template <typename T2>
ref<T2> cast() const {
return ref<T2>(std::dynamic_pointer_cast<T2>(p));
}
template <typename T2>
std::shared_ptr<T2> dynamic_pointer_cast() const {
return std::dynamic_pointer_cast<T2>(p);
}
template <typename T2>
operator ref<T2>() const {
return ref<T2>((std::shared_ptr<T2>)p);
}
private:
template <typename T2, typename... Args>
friend ref<T2> make_ref(Args&&... args);
};
template <typename T, typename... Args>
inline ref<T> make_ref(Args&&... args) {
auto p = std::make_shared<T>(std::forward<Args>(args)...);
return ref<T>(p);
}
} // namespace nix
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