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// This file is part of CAF, the C++ Actor Framework. See the file LICENSE in
// the main distribution directory for license terms and copyright or visit
// https://github.com/actor-framework/actor-framework/blob/master/LICENSE.
#pragma once
#include <iterator>
#include "caf/detail/type_traits.hpp"
namespace caf {
template <class T>
class input_range {
public:
virtual ~input_range() {
// nop
}
input_range() = default;
input_range(const input_range&) = default;
input_range& operator=(const input_range&) = default;
class iterator : public std::iterator<std::input_iterator_tag, T> {
public:
iterator(input_range* range) : xs_(range) {
if (xs_)
advance();
else
x_ = nullptr;
}
iterator(const iterator&) = default;
iterator& operator=(const iterator&) = default;
bool operator==(const iterator& other) const {
return xs_ == other.xs_;
}
bool operator!=(const iterator& other) const {
return !(*this == other);
}
T& operator*() {
return *x_;
}
T* operator->() {
return x_;
}
iterator& operator++() {
advance();
return *this;
}
iterator operator++(int) {
iterator copy{xs_};
advance();
return copy;
}
private:
void advance() {
x_ = xs_->next();
if (!x_)
xs_ = nullptr;
}
input_range* xs_;
T* x_;
};
virtual T* next() = 0;
iterator begin() {
return this;
}
iterator end() const {
return nullptr;
}
};
template <class I>
class input_range_impl : public input_range<detail::value_type_of_t<I>> {
public:
using value_type = detail::value_type_of_t<I>;
input_range_impl(I first, I last) : pos_(first), last_(last) {
// nop
}
value_type* next() override {
return (pos_ == last_) ? nullptr : &(*pos_++);
}
private:
I pos_;
I last_;
};
/// @relates input_range
template <class I>
input_range_impl<I> make_input_range(I first, I last) {
return {first, last};
}
} // namespace caf
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