#pragma once

#include <stdexcept>

namespace pid_control
{

struct VariantToDoubleVisitor
{
    template <typename T>
    std::enable_if_t<std::is_arithmetic<T>::value, double>
        operator()(const T& t) const
    {
        return static_cast<double>(t);
    }

    template <typename T>
    std::enable_if_t<!std::is_arithmetic<T>::value, double>
        operator()(const T& t) const
    {
        throw std::invalid_argument("Cannot translate type to double");
    }
};

} // namespace pid_control