optional.hpp

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/*------------------------------------------------------------------------------
    Copyright Butterfly Energy Systems 2014-2015, 2022.
    Distributed under the Boost Software License, Version 1.0.
    http://www.boost.org/LICENSE_1_0.txt
------------------------------------------------------------------------------*/
 
#ifndef CPPWAMP_TYPES_OPTIONAL_HPP
#define CPPWAMP_TYPES_OPTIONAL_HPP
 
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
 
#include <optional>
#include "../api.hpp"
#include "../variant.hpp"
 
namespace wamp
{
 
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
template <typename T>
CPPWAMP_API void convert(FromVariantConverter& conv, std::optional<T>& opt)
{
    const auto& variant = conv.variant();
    if (!variant)
        opt.reset();
    else
        opt = variant.to<T>();
}
 
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
template <typename T>
CPPWAMP_API void convert(ToVariantConverter& conv, std::optional<T>& opt)
{
    auto& variant = conv.variant();
    if (!opt)
        variant = null;
    else
        variant = Variant::from(*opt);
}
 
 
//------------------------------------------------------------------------------
// Comparison Operators
//------------------------------------------------------------------------------
 
template <typename T>
CPPWAMP_API bool operator==(const Variant& v, const std::optional<T> o)
{
    return !o ? !v : (v == *o);
}
 
template <typename T>
CPPWAMP_API bool operator==(const std::optional<T> o, const Variant& v)
{
    return v == o;
}
 
template <typename T>
CPPWAMP_API bool operator!=(const Variant& v, const std::optional<T> o)
{
    return !o ? !!v : (v != *o);
}
 
template <typename T>
CPPWAMP_API bool operator!=(const std::optional<T> o, const Variant& v)
{
    return v != o;
}
 
} // namespace wamp
 
#endif // CPPWAMP_TYPES_OPTIONAL_HPP