From 549e0b1e64d4c4d9d7cc6d87323e892e0e6f0cd1 Mon Sep 17 00:00:00 2001
From: Frank Dellaert <dellaert@gmail.com>
Date: Tue, 3 Jan 2023 15:14:41 -0500
Subject: [PATCH] Fix argument to const &

---
 gtsam/linear/NoiseModel.cpp | 7 ++++---
 gtsam/linear/NoiseModel.h   | 2 +-
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/gtsam/linear/NoiseModel.cpp b/gtsam/linear/NoiseModel.cpp
index 8bcef6fcc..7108a7660 100644
--- a/gtsam/linear/NoiseModel.cpp
+++ b/gtsam/linear/NoiseModel.cpp
@@ -47,8 +47,9 @@ void updateAb(MATRIX& Ab, int j, const Vector& a, const Vector& rd) {
 
 /* ************************************************************************* */
 // check *above the diagonal* for non-zero entries
-boost::optional<Vector> checkIfDiagonal(const Matrix M) {
+boost::optional<Vector> checkIfDiagonal(const Matrix& M) {
   size_t m = M.rows(), n = M.cols();
+  assert(m > 0);
   // check all non-diagonal entries
   bool full = false;
   size_t i, j;
@@ -92,7 +93,7 @@ Gaussian::shared_ptr Gaussian::SqrtInformation(const Matrix& R, bool smart) {
       return Diagonal::Sigmas(diagonal->array().inverse(), true);
   }
   // NOTE(frank): only reaches here if !(smart && diagonal)
-  return shared_ptr(new Gaussian(R.rows(), R));
+  return boost::make_shared<Gaussian>(R.rows(), R);
 }
 
 /* ************************************************************************* */
@@ -108,7 +109,7 @@ Gaussian::shared_ptr Gaussian::Information(const Matrix& information, bool smart
   else {
     Eigen::LLT<Matrix> llt(information);
     Matrix R = llt.matrixU();
-    return shared_ptr(new Gaussian(n, R));
+    return boost::make_shared<Gaussian>(n, R);
   }
 }
 
diff --git a/gtsam/linear/NoiseModel.h b/gtsam/linear/NoiseModel.h
index 5a29e5d7d..7bcf808e5 100644
--- a/gtsam/linear/NoiseModel.h
+++ b/gtsam/linear/NoiseModel.h
@@ -732,7 +732,7 @@ namespace gtsam {
     };
 
     // Helper function
-    GTSAM_EXPORT boost::optional<Vector> checkIfDiagonal(const Matrix M);
+    GTSAM_EXPORT boost::optional<Vector> checkIfDiagonal(const Matrix& M);
 
   } // namespace noiseModel