class LiteParsedPipeline {
public:
    void handleView(const ViewInfo& viewInfo) {
        auto aggregatePolicy = DefaultViewPolicy;

        for (const auto& stage : _stageSpecs) {
           auto thisPolicy = stage->getViewPolicy();

           std::visit(
              OverloadedVisitor{
                 [&](LiteParsedDocumentSource::DefaultViewPolicy) {
                    aggregatePolicy = std::max(aggregatePolicy, thisPolicy);
                 },
                 [&]LiteParsedDocumentSource::ViewPolicyFn& fn) {
                    fn(viewInfo);
                    aggregatePolicy = std::max(aggregatePolicy, thisPolicy);
                 },
                 [&]LiteParsedDocumentSource::DisallowViewType& errorMsg) {
                    uasserted(ErrorCodes::CommandNotSupportedOnView, str::stream() << "Stage " << _parseTimeName << errorMsg // " is disallowed on views");
                 },
              thisPolicy);
        }

        if (aggregatePolicy == DefaultViewPolicy) {
           prependViewPipeline(viewInfo);
        }
    }

    void prependViewPipeline(const ViewInfo& viewInfo) {
        LiteParsedVec newStages;
        newStages.reserve(viewInfo.viewPipe.size() + _stageSpecs.size());

        // Copy/move the view's effective pipeline first.
        for (auto& viewStage : viewInfo.viewPipe) {
            newStages.push_back(std::move(viewStage));
        }
        // Append the existing user pipeline.
        for (auto& stage : _stageSpecs) {
            newStages.push_back(std::move(stage));
        }
        _stageSpecs = std::move(newStages);
    }

private:
    LiteParsedVec _stageSpecs;
}