Merge branch 'update/eigen-3.4' of github.com:stan-dev/math into update/eigen-3.4

Author: SteveBronder

stan/math/fwd/fun/mdivide_right.hpp

@@ -54,9 +54,9 @@ mdivide_right(const EigMat1& b, const EigMat2& A) {
     }
   }
   auto A_mult_inv_b = mdivide_right(val_b, val_A).eval();
-  promote_scalar_t<fvar<inner_ret_t>, decltype(A_mult_inv_b)> ret(A_mult_inv_b.rows(), A_mult_inv_b.cols());
-  ret.val() = A_mult_inv_b;
-  ret.d() = mdivide_right(deriv_b, val_A)
+  promote_scalar_t<fvar<inner_ret_t>, decltype(A_mult_inv_b)>
+ret(A_mult_inv_b.rows(), A_mult_inv_b.cols()); ret.val() = A_mult_inv_b; ret.d()
+= mdivide_right(deriv_b, val_A)
       - multiply(A_mult_inv_b, mdivide_right(deriv_A, val_A));
   return ret;
 }
@@ -70,10 +70,12 @@ template <typename EigMat1, typename EigMat2,
             check_square("mdivide_right", "A", A);
             check_multiplicable("mdivide_right", "b", b, "A", A);
             if (A.size() == 0) {
-              using ret_type = decltype(A.transpose().template cast<T_return>().lu().solve(b.template cast<T_return>().transpose()).transpose().eval());
-              return ret_type{b.rows(), 0};
+              using ret_type = decltype(A.transpose().template
+cast<T_return>().lu().solve(b.template
+cast<T_return>().transpose()).transpose().eval()); return ret_type{b.rows(), 0};
             }
-            return A.transpose().template cast<T_return>().lu().solve(b.template cast<T_return>().transpose()).transpose().eval();
+            return A.transpose().template cast<T_return>().lu().solve(b.template
+cast<T_return>().transpose()).transpose().eval();
           }
 
 template <typename EigMat1, typename EigMat2,
@@ -85,10 +87,12 @@ template <typename EigMat1, typename EigMat2,
             check_square("mdivide_right", "A", A);
             check_multiplicable("mdivide_right", "b", b, "A", A);
             if (A.size() == 0) {
-              using ret_type = decltype(A.transpose().template cast<T_return>().lu().solve(b.template cast<T_return>().transpose()).transpose().eval());
-              return ret_type{b.rows(), 0};
+              using ret_type = decltype(A.transpose().template
+cast<T_return>().lu().solve(b.template
+cast<T_return>().transpose()).transpose().eval()); return ret_type{b.rows(), 0};
             }
-            return A.transpose().template cast<T_return>().lu().solve(b.template cast<T_return>().transpose()).transpose().eval();
+            return A.transpose().template cast<T_return>().lu().solve(b.template
+cast<T_return>().transpose()).transpose().eval();
           }
 */
 }  // namespace math

stan/math/prim/fun/mdivide_right.hpp

@@ -22,16 +22,26 @@ namespace math {
  */
 template <typename EigMat1, typename EigMat2,
           require_all_eigen_t<EigMat1, EigMat2>* = nullptr>
-inline auto
-mdivide_right(const EigMat1& b, const EigMat2& A) {
+inline auto mdivide_right(const EigMat1& b, const EigMat2& A) {
   using T_return = return_type_t<EigMat1, EigMat2>;
   check_square("mdivide_right", "A", A);
   check_multiplicable("mdivide_right", "b", b, "A", A);
   if (A.size() == 0) {
-    using ret_type = decltype(A.transpose().template cast<T_return>().lu().solve(b.template cast<T_return>().transpose()).transpose().eval());
+    using ret_type
+        = decltype(A.transpose()
+                       .template cast<T_return>()
+                       .lu()
+                       .solve(b.template cast<T_return>().transpose())
+                       .transpose()
+                       .eval());
     return ret_type{b.rows(), 0};
   }
-  return A.transpose().template cast<T_return>().lu().solve(b.template cast<T_return>().transpose()).transpose().eval();
+  return A.transpose()
+      .template cast<T_return>()
+      .lu()
+      .solve(b.template cast<T_return>().transpose())
+      .transpose()
+      .eval();
 }
 
 }  // namespace math

test/unit/math/mix/fun/mdivide_right_test.cpp

@@ -74,7 +74,7 @@ TEST(MathMixMatFun, mdivideRight_rowvector_matrix1) {
   Eigen::RowVectorXd g(2);
   g << 1, 1;
 
-stan::test::expect_ad(f, g, b);
+  stan::test::expect_ad(f, g, b);
   // vector, matrix
   /*
   for (const auto& m : std::vector<Eigen::MatrixXd>{b}) {