change how proxy is cast in cpu predictor

Author: yoquinjo

src/predictor/cpu_predictor.cc

@@ -396,12 +396,8 @@ class CPUPredictor : public Predictor {
   bool InplacePredict(std::shared_ptr<DMatrix> p_m, const gbm::GBTreeModel &model, float missing,
                       PredictionCacheEntry *out_preds, uint32_t tree_begin,
                       unsigned tree_end) const override {
-    //auto proxy = dynamic_cast<data::DMatrixProxy *>(p_m.get());
-    auto proxy = new std::shared_ptr<xgboost::DMatrix>(new xgboost::data::DMatrixProxy);
-    if (!proxy) {
-      fprintf (stderr, "InplacePredict: proxy is null cpu variant");
-      exit(1);
-    }
+    auto proxy = dynamic_cast<data::DMatrixProxy *>(p_m.get());
+    //auto proxy = new std::shared_ptr<xgboost::DMatrix>(new xgboost::data::DMatrixProxy);
     auto x = proxy->Adapter();
     if (x.type() == typeid(std::shared_ptr<data::DenseAdapter>)) {
       this->DispatchedInplacePredict<data::DenseAdapter, kBlockOfRowsSize>(