atomic_optional.h

#ifndef ATOMIC_OPTIONAL_H
#define ATOMIC_OPTIONAL_H
 
#include <type_traits>
#include <utility>
#include <stdexcept>
#include <atomic>
 
namespace ara
{
    namespace exec
    {
        namespace helper
        {
            template <typename T>
            class AtomicOptional
            {
            private:
                std::atomic<T> mValue;
                std::atomic<bool> mHasValue;
 
            public:
                AtomicOptional() noexcept : mHasValue{false}
                {
                }
 
                constexpr AtomicOptional(T value) noexcept : mValue{value},
                                                             mHasValue{true}
                {
                }
 
                ~AtomicOptional() noexcept = default;
                AtomicOptional &operator=(const AtomicOptional& other) = delete;
 
                AtomicOptional &operator=(T value) noexcept
                {
                    mValue = value;
                    mHasValue = true;
 
                    return *this;
                }
 
                void Reset() noexcept
                {
                    mHasValue = false;
                }
 
                bool HasValue() const noexcept
                {
                    return mHasValue;
                }
 
                T Value() const
                {
                    if (mHasValue)
                    {
                        return mValue.load();
                    }
                    else
                    {
                        throw std::runtime_error("Optional contains no value.");
                    }
                }
            };
        }
    }
}
 
#endif