Bijection.h

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* libscopehal                                                                                                          *
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#ifndef Bijection_h
#define Bijection_h
 
template<class T1, class T2, typename Compare1 = std::less<T1>, typename Compare2 = std::less<T2> >
class Bijection
{
public:
 
    typedef std::map<T1, T2, Compare1> forwardType;
 
    typedef std::map<T2, T1, Compare2> reverseType;
 
    typename forwardType::const_iterator begin()
    { return m_forwardMap.begin(); }
 
    typename forwardType::const_iterator end()
    { return m_forwardMap.end(); }
 
    void emplace(T1 a, T2 b)
    {
        m_forwardMap[a] = b;
        m_reverseMap[b] = a;
    }
 
    const T1& operator[](T2 key)
    { return m_reverseMap[key]; }
 
    const T2& operator[](T1 key)
    { return m_forwardMap[key]; }
 
    bool HasEntry(T1 key)
    { return m_forwardMap.find(key) != m_forwardMap.end(); }
 
    bool HasEntry(T2 key)
    { return m_reverseMap.find(key) != m_reverseMap.end(); }
 
    void clear()
    {
        m_forwardMap.clear();
        m_reverseMap.clear();
    }
 
    void erase(T1 key)
    {
        auto value = m_forwardMap[key];
        m_forwardMap.erase(key);
        m_reverseMap.erase(value);
    }
 
    void erase(T2 key)
    {
        auto value = m_reverseMap[key];
        m_reverseMap.erase(key);
        m_forwardMap.erase(value);
    }
 
    void replace(T2 oldval, T2 newval)
    {
        T1 key = m_reverseMap[oldval];
        m_reverseMap.erase(oldval);
        m_forwardMap[key] = newval;
        m_reverseMap[newval] = key;
    }
 
    size_t size()
    { return m_forwardMap.size(); }
 
protected:
 
    forwardType m_forwardMap;
 
    reverseType m_reverseMap;
};
 
#endif