use [[maybe_unused]] some more

dune/xt/common/fixed_map.hh

@@ -125,7 +125,7 @@ private:
 
   typedef FixedMap<key_imp, T, nin> ThisType;
 
-  std::string range_error_message(key_imp key) const
+  std::string range_error_message([[maybe_unused]] key_imp key) const
   {
     std::stringstream ss;
     if constexpr (std::is_convertible<key_imp, std::string>::value) {

dune/xt/common/string.hh

@@ -129,10 +129,8 @@ std::string whitespaceify(const T& t, const char whitespace = ' ')
 {
   const std::string s = to_string(t);
   std::string ret = "";
-  for (auto ii : value_range(s.size())) {
+  for ([[maybe_unused]] auto ii : value_range(s.size()))
     ret += whitespace;
-    (void)ii;
-  }
   return ret;
 } // ... whitespaceify(...)
 

dune/xt/functions/interfaces/element-functions.hh

@@ -417,10 +417,11 @@ private:
   template <class FullType, class SingleType>
   void single_derivative_helper_call(const std::vector<FullType>& val,
                                      const size_t row,
-                                     const size_t col,
+                                     [[maybe_unused]] const size_t col,
                                      std::vector<SingleType>& ret) const
   {
     if constexpr (rC == 1) {
+      assert(col == 0);
       for (size_t ii = 0; ii < val.size(); ++ii)
         ret[ii] = val[ii][row];
     } else {
@@ -705,9 +706,10 @@ public:
 private:
   template <class FullType>
   static SingleDerivativeRangeType
-  single_derivative_helper_call(const FullType& val, const size_t row, const size_t col)
+  single_derivative_helper_call(const FullType& val, const size_t row, [[maybe_unused]] const size_t col)
   {
     if constexpr (rC == 1) {
+      assert(col == 0);
       return val[row];
     } else {
       SingleDerivativeRangeType ret;

dune/xt/grid/information.hh

@@ -83,10 +83,8 @@ size_t max_number_of_neighbors(const GridLayerType& grid_layer)
   size_t maxNeighbours = 0;
   for (auto&& entity : elements(grid_layer)) {
     size_t neighbours = 0;
-    for (auto&& intersection : intersections(grid_layer, entity)) {
-      (void)intersection; // silence unused variable warning
+    for ([[maybe_unused]] auto&& intersection : intersections(grid_layer, entity))
       ++neighbours;
-    }
     maxNeighbours = std::max(maxNeighbours, neighbours);
   }
   return maxNeighbours;

dune/xt/test/common/timings.cc

@@ -45,9 +45,8 @@ GTEST_TEST(ProfilerTest, Timing)
 GTEST_TEST(ProfilerTest, ScopedTiming)
 {
   const auto dvalue_range = value_range(1, 4);
-  for ([[maybe_unused] auto i : dvalue_range) {
+  for ([[maybe_unused]] auto i : dvalue_range)
     scoped_busywait("ProfilerTest.ScopedTiming", wait_ms);
-  }
   EXPECT_GE(DXTC_TIMINGS.walltime("ProfilerTest.ScopedTiming"), long(dvalue_range.size() * wait_ms));
 }
 

dune/xt/test/grid/periodic_gridview.cc

@@ -80,8 +80,7 @@ struct PeriodicViewTest : public testing::Test
     const PeriodicGridViewType periodic_grid_view(grid_view, periodic_directions);
 
     // check interface
-    const GridType& test_grid = periodic_grid_view.grid();
-    (void)test_grid;
+    [[maybe_unused]] const GridType& test_grid = periodic_grid_view.grid();
     const IndexSet& index_set = periodic_grid_view.indexSet();
     const int codim0_size = periodic_grid_view.size(0);
     EXPECT_EQ(grid_view.size(0), codim0_size);
@@ -95,8 +94,7 @@ struct PeriodicViewTest : public testing::Test
     EXPECT_EQ(grid_view.overlapSize(1), periodic_grid_view.overlapSize(1));
     EXPECT_EQ(grid_view.ghostSize(0), periodic_grid_view.ghostSize(0));
     EXPECT_EQ(grid_view.ghostSize(1), periodic_grid_view.ghostSize(1));
-    const CollectiveCommunication& test_comm = periodic_grid_view.comm();
-    (void)test_comm;
+    [[maybe_unused]] const CollectiveCommunication& test_comm = periodic_grid_view.comm();
 
 
     size_t neighbor_count = 0;
@@ -106,8 +104,7 @@ struct PeriodicViewTest : public testing::Test
     for (auto&& element : elements(periodic_grid_view)) {
       EXPECT_TRUE(periodic_grid_view.contains(element));
       EXPECT_TRUE(index_set.contains(element));
-      const auto sub_index = index_set.subIndex(element, 0, 1);
-      (void)sub_index;
+      [[maybe_unused]] const auto sub_index = index_set.subIndex(element, 0, 1);
       // iterate over all intersections on current element
       for (auto&& intersection : intersections(periodic_grid_view, element)) {
         if (intersection.neighbor()) {