49 lines
1.1 KiB
C++
49 lines
1.1 KiB
C++
#pragma once
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#include "utils/iterator/composable.hpp"
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#include "utils/iterator/iterator_base.hpp"
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namespace iter
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{
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// Class which wraps iterator and hides it's type. It actualy does this by
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// dynamicly allocating iterator on heap.
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// T - type of return value
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template <class T>
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class Virtual : public Composable<T, Virtual<T>>
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{
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public:
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Virtual() = delete;
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// Virtual operation is designed to be used in chained calls which operate
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// on a
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// iterator. Virtual will in that usecase receive other iterator by value
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// and
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// std::move is a optimization for it.
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template <class I>
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Virtual(I &&iter) : it(std::make_unique<I>(std::move(iter)))
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{
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}
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Virtual(Virtual &&m) : it(std::move(m.it)) {}
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~Virtual() {}
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Option<T> next() { return it.get()->next(); }
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Count count() { return it.get()->count(); }
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private:
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std::unique_ptr<IteratorBase<T>> it;
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};
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template <class I>
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auto make_virtual(I &&iter)
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{
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// Compiler cant deduce type T. decltype is here to help with it.
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return Virtual<decltype(iter.next().take())>(std::move(iter));
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}
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}
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