Fix unused local typedef warning in matrix exponential
diff --git a/unsupported/Eigen/src/MatrixFunctions/MatrixExponential.h b/unsupported/Eigen/src/MatrixFunctions/MatrixExponential.h
index a28aa96..f4e0428 100644
--- a/unsupported/Eigen/src/MatrixFunctions/MatrixExponential.h
+++ b/unsupported/Eigen/src/MatrixFunctions/MatrixExponential.h
@@ -284,12 +284,13 @@
 struct matrix_exp_computeUV<MatrixType, long double> {
   template <typename ArgType>
   static void run(const ArgType& arg, MatrixType& U, MatrixType& V, int& squarings) {
-    using Scalar = typename traits<MatrixType>::Scalar;
 #if LDBL_MANT_DIG == 53  // double precision
     matrix_exp_computeUV<MatrixType, double>::run(arg, U, V, squarings);
 
 #else
 
+    using Scalar = typename traits<MatrixType>::Scalar;
+
     using std::frexp;
     using std::pow;
     const long double l1norm = arg.cwiseAbs().colwise().sum().maxCoeff();