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/**
* @file optional.hpp
* @author Felix Morgner (felix.morgner@gmail.com)
* @since 1.0.0
*/
#ifndef WANDA_OPTIONAL_HPP
#define WANDA_OPTIONAL_HPP
#include <optional>
namespace wanda::std_ext
{
/**
* @brief A type to represent a computation that could fail
*/
struct failable
{
/**
* @brief A factory to create a successful computation
*/
constexpr static auto success() { return failable{false}; }
/**
* @brief A factory to create a failed computation
*/
constexpr static auto failure() { return failable{true}; }
/**
* @brief Execute the given handler if the computation failed
*/
template<typename Handler>
constexpr void operator||(Handler handler) const
{
if (m_failed)
{
handler();
}
}
private:
constexpr explicit failable(bool failed)
: m_failed{failed} {};
bool const m_failed;
};
/**
* @brief Unwrap the given optional object, if present, and pass it to the handler
*
* @return A successful computation iff. the object was present, a failed computation otherwise.
*/
template<typename ObjectType, typename HandlerType>
auto with(std::optional<ObjectType> && object, HandlerType handler)
{
if (object)
{
handler(object.value());
return failable::success();
}
return failable::failure();
}
} // namespace wanda::std_ext
#endif
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