From bb6033b17e56c7c66feee35cba25f2f91abf745d Mon Sep 17 00:00:00 2001
From: charlesAuguste <charles.auguste@ymail.com>
Date: Sun, 23 Aug 2020 14:26:49 +0100
Subject: [PATCH] Forgotten reference.

---
 src/treelearner/feature_histogram.hpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/treelearner/feature_histogram.hpp b/src/treelearner/feature_histogram.hpp
index 954086459bb2..261ec08e1464 100644
--- a/src/treelearner/feature_histogram.hpp
+++ b/src/treelearner/feature_histogram.hpp
@@ -764,7 +764,7 @@ class FeatureHistogram {
   template <bool USE_MC, bool USE_L1, bool USE_MAX_OUTPUT, bool USE_SMOOTHING>
   static double CalculateSplittedLeafOutput(
       double sum_gradients, double sum_hessians, double l1, double l2,
-      double max_delta_step, const BasicConstraint constraints,
+      double max_delta_step, const BasicConstraint& constraints,
       double smoothing, data_size_t num_data, double parent_output) {
     double ret = CalculateSplittedLeafOutput<USE_L1, USE_MAX_OUTPUT, USE_SMOOTHING>(
         sum_gradients, sum_hessians, l1, l2, max_delta_step, smoothing, num_data, parent_output);