ref.h

Go to the documentation of this file.

// Copyright (c) 2020 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
#ifndef BITCOIN_UTIL_REF_H
#define BITCOIN_UTIL_REF_H
 
#include <util/check.h>
 
#include <typeindex>
 
namespace util {
 
class Ref
{
public:
    Ref() = default;
    template<typename T> Ref(T& value) { Set(value); }
    template<typename T> T& Get() const { CHECK_NONFATAL(Has<T>()); return *static_cast<T*>(m_value); }
    template<typename T> void Set(T& value) { m_value = &value; m_type = std::type_index(typeid(T)); }
    template<typename T> bool Has() const { return m_value && m_type == std::type_index(typeid(T)); }
    void Clear() { m_value = nullptr; m_type = std::type_index(typeid(void)); }
 
private:
    void* m_value = nullptr;
    std::type_index m_type = std::type_index(typeid(void));
};
 
} // namespace util
 
#endif // BITCOIN_UTIL_REF_H