Enumerator.StackComposite.hxx

 
//
//  Copyright Phoenix Contact GmbH & Co. KG
//
#pragma once
#include "Arp/Base/Core/Arp.hpp"
#include "Arp/Base/Core/Exception.hpp"
#include "Arp/Base/Core/Detail/Enumerator.hxx"
#include <stack>
 
namespace Arp { namespace Base { namespace Core
{
 
template<class T>
class Enumerator<T>::StackComposite : public IEnumerator<T>
{
private: // usings
    using Stack = std::stack<typename IEnumerator<T>::Ptr>;
 
public: // construction/destruction
    StackComposite(void);
    StackComposite(const StackComposite& arg) = delete;
    StackComposite(StackComposite&& arg)noexcept;
    StackComposite& operator=(const StackComposite& arg) = delete;
    StackComposite& operator=(StackComposite&& arg)noexcept;
    ~StackComposite(void)override;
 
public: // overridden operations
    bool    MoveNext(void)override;
    T       GetCurrent(void)override;
 
public: //  operations
    void    Push(typename IEnumerator<T>::Ptr enumerator);
    size_t  GetSize(void)const;
 
private: // fields
    Stack   enumerators;
};
 
// inline methods of class Enumerator<T>::StackComposite
 
template<class T>
inline Enumerator<T>::StackComposite::StackComposite() = default;
 
template<class T>
inline Enumerator<T>::StackComposite::StackComposite(StackComposite&& arg)noexcept = default;
 
template<class T>
inline typename Enumerator<T>::StackComposite& Enumerator<T>::StackComposite::operator=(StackComposite&& arg) noexcept = default;
 
template<class T>
inline Enumerator<T>::StackComposite::~StackComposite() = default;
 
// inherited doc
template<class T>
inline bool Enumerator<T>::StackComposite::MoveNext()
{
    while (!this->enumerators.empty())
    {
        if (this->enumerators.top()->MoveNext())
        {
            return true;
        }
        // else must pop last enumerator
        this->enumerators.pop();
    }
    // reaching this point means stack is empty
    return false;
}
 
// inherited doc
template<class T>
inline T Enumerator<T>::StackComposite::GetCurrent()
{
    if (this->enumerators.empty())
    {
        throw Exception("Enumerator<T>::StackComposite::GetCurrent(): StackComposite enumerators is empty or enumerating has ended yet");
    }
    return this->enumerators.top()->GetCurrent();
}
 
template<class T>
inline void Enumerator<T>::StackComposite::Push(typename IEnumerator<T>::Ptr enumerator)
{
    if (!enumerator)
    {
        return;
    }
    this->enumerators.emplace(std::move(enumerator));
}
 
template<class T>
inline size_t Enumerator<T>::StackComposite::GetSize()const
{
    return this->enumerators.size();
}
 
}}} // end of namespace Arp::Base::Core