Gauge.h

#pragma once
 
#include <xrpl/beast/insight/GaugeImpl.h>
 
#include <memory>
#include <utility>
 
namespace beast::insight {

class Gauge final
{
public:
    using value_type = GaugeImpl::value_type;
    using difference_type = GaugeImpl::difference_type;

    Gauge() = default;

    explicit Gauge(std::shared_ptr<GaugeImpl> impl) : impl_(std::move(impl))
    {
    }

    void
    set(value_type value) const
    {
        if (impl_)
            impl_->set(value);
    }
 
    // This is a write-through handle: assignment sets the value of the
    // referenced metric.  It is const-qualified and returns Gauge const&
    // (a non-const Gauge& would require a const_cast), so it does not follow
    // the conventional assignment-operator signature.
    // NOLINTNEXTLINE(misc-unconventional-assign-operator)
    Gauge const&
    operator=(value_type value) const
    {
        set(value);
        return *this;
    }


    void
    increment(difference_type amount) const
    {
        if (impl_)
            impl_->increment(amount);
    }
 
    Gauge const&
    operator+=(difference_type amount) const
    {
        increment(amount);
        return *this;
    }
 
    Gauge const&
    operator-=(difference_type amount) const
    {
        increment(-amount);
        return *this;
    }
 
    Gauge const&
    operator++() const
    {
        increment(1);
        return *this;
    }
 
    Gauge const&
    operator++(int) const
    {
        increment(1);
        return *this;
    }
 
    Gauge const&
    operator--() const
    {
        increment(-1);
        return *this;
    }
 
    Gauge const&
    operator--(int) const
    {
        increment(-1);
        return *this;
    }

 
    [[nodiscard]] std::shared_ptr<GaugeImpl> const&
    impl() const
    {
        return impl_;
    }
 
private:
    std::shared_ptr<GaugeImpl> impl_;
};
 
}  // namespace beast::insight