// Copyright The OpenTelemetry Authors // SPDX-License-Identifier: Apache-2.0 #pragma once #ifndef ENABLE_METRICS_PREVIEW # include "opentelemetry/metrics/observer_result.h" OPENTELEMETRY_BEGIN_NAMESPACE namespace metrics { class AsynchronousInstrument {}; template class ObservableCounter : public AsynchronousInstrument {}; template class ObservableGauge : public AsynchronousInstrument {}; template class ObservableUpDownCounter : public AsynchronousInstrument {}; } // namespace metrics OPENTELEMETRY_END_NAMESPACE #endif