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#ifndef INCLUDED_WRITER_
#define INCLUDED_WRITER_
// use return_value if an expression is passed to co_return
#include <iostream>
#include <optional>
#include "../../promisebase/promisebase.h"
//writer
struct Writer
{
using ValueType = std::optional<std::string>;
private:
class State: public PromiseBase<Writer, State>
{
ValueType d_value;
public:
std::suspend_always yield_value(ValueType &value);
void return_void();
ValueType const &value() const;
};
std::coroutine_handle<State> d_handle;
public:
using promise_type = State;
explicit Writer(std::coroutine_handle<State> handle);
~Writer();
ValueType const &next();
};
inline std::suspend_always Writer::State::yield_value(ValueType &value)
{
d_value = std::move(value);
return {};
}
//=
inline void Writer::State::return_void()
{
d_value = ValueType{};
}
inline Writer::ValueType const &Writer::State::value() const
{
return d_value;
}
inline Writer::Writer(std::coroutine_handle<State> handle)
:
d_handle(handle)
{}
inline Writer::~Writer()
{
if (d_handle)
d_handle.destroy();
}
#endif
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