From 83b0ad2d642f4591163af0e2b83debe8b0ccb033 Mon Sep 17 00:00:00 2001
From: Giacomo Fiorin <giacomo.fiorin@gmail.com>
Date: Tue, 18 Jul 2023 10:09:29 -0400
Subject: [PATCH] Cast to bool when testing value of enum class flag

---
 src/colvar_rotation_derivative.h | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/colvar_rotation_derivative.h b/src/colvar_rotation_derivative.h
index a12786af2..162067536 100644
--- a/src/colvar_rotation_derivative.h
+++ b/src/colvar_rotation_derivative.h
@@ -37,10 +37,10 @@ inline constexpr rotation_derivative_dldq operator|(rotation_derivative_dldq Lhs
     static_cast<std::underlying_type<rotation_derivative_dldq>::type>(Rhs));
 }
 
-inline constexpr rotation_derivative_dldq operator&(rotation_derivative_dldq Lhs, rotation_derivative_dldq Rhs) {
-  return static_cast<rotation_derivative_dldq>(
-    static_cast<std::underlying_type<rotation_derivative_dldq>::type>(Lhs) &
-    static_cast<std::underlying_type<rotation_derivative_dldq>::type>(Rhs));
+inline constexpr bool operator&(rotation_derivative_dldq Lhs, rotation_derivative_dldq Rhs)
+{
+  return (static_cast<std::underlying_type<rotation_derivative_dldq>::type>(Lhs) &
+          static_cast<std::underlying_type<rotation_derivative_dldq>::type>(Rhs));
 }
 
 /// \brief Helper class for calculating the derivative of rotation
@@ -79,7 +79,7 @@ struct rotation_derivative {
     *                           with respect to atoms.
     */
   void prepare_derivative(rotation_derivative_dldq require_dl_dq) {
-    if (static_cast<std::underlying_type<rotation_derivative_dldq>::type>(require_dl_dq & rotation_derivative_dldq::use_dl)) {
+    if (require_dl_dq & rotation_derivative_dldq::use_dl) {
       const auto &Q0 = m_rot.S_eigvec[0].data;
       tmp_Q0Q0[0][0] = Q0[0] * Q0[0];
       tmp_Q0Q0[0][1] = Q0[0] * Q0[1];
@@ -98,7 +98,7 @@ struct rotation_derivative {
       tmp_Q0Q0[3][2] = Q0[3] * Q0[2];
       tmp_Q0Q0[3][3] = Q0[3] * Q0[3];
     }
-    if (static_cast<std::underlying_type<rotation_derivative_dldq>::type>(require_dl_dq & rotation_derivative_dldq::use_dq)) {
+    if (require_dl_dq & rotation_derivative_dldq::use_dq) {
       const auto &Q0 = m_rot.S_eigvec[0].data;
       const auto &Q1 = m_rot.S_eigvec[1].data;
       const auto &Q2 = m_rot.S_eigvec[2].data;