56 lines
1.9 KiB
C++
56 lines
1.9 KiB
C++
#ifndef ARBUTILS_BORROWED_PTR_HPP
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#define ARBUTILS_BORROWED_PTR_HPP
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#include <memory>
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namespace ArbUt {
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/// A borrowed pointer is used to indicate a pointer that is not owned by an object, but instead borrowed from
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/// another owning object that is assumed to always be kept alive during the entire lifetime of the borrowing
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/// object.
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template <class T> class borrowed_ptr {
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private:
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T* _raw;
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public:
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inline borrowed_ptr<T>() : _raw(nullptr){};
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inline borrowed_ptr<T>(T* ptr) : _raw(ptr){};
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inline borrowed_ptr(const borrowed_ptr<T>& other) : _raw(other._raw){};
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inline borrowed_ptr(const std::unique_ptr<T>& other) : _raw(other.get()){};
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~borrowed_ptr() = default;
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inline borrowed_ptr<T>& operator=(const borrowed_ptr<T>& rhs) {
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_raw = rhs._raw;
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return *this;
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}
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inline T* operator->() const noexcept { return _raw; }
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inline T* GetRaw() const noexcept { return _raw; }
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inline bool operator==(const borrowed_ptr& rhs) const { return _raw == rhs._raw; }
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inline bool operator!=(const borrowed_ptr& rhs) const { return _raw != rhs._raw; }
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[[nodiscard]] inline constexpr bool IsNull() const noexcept { return _raw == nullptr; }
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template <class TCast> inline borrowed_ptr<TCast> As() const {
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auto cast = dynamic_cast<TCast>(_raw);
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return borrowed_ptr<TCast>(cast);
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}
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template <class TCast> inline bool TryAs(borrowed_ptr<TCast>& out) const {
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auto cast = dynamic_cast<TCast>(_raw);
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if (cast == nullptr)
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return false;
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out = borrowed_ptr<TCast>(cast);
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return true;
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}
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template <class TCast> inline borrowed_ptr<TCast> ForceAs() const {
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auto cast = reinterpret_cast<TCast>(_raw);
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return borrowed_ptr<TCast>(cast);
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}
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};
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}
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#endif // ARBUTILS_BORROWED_PTR_HPP
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