cpp20 if with initializer

src/field/field_data.cxx

@@ -189,12 +189,11 @@ void FieldData::addBndryGenerator(FieldGeneratorPtr gen, BndryLoc location) {
 }
 
 FieldGeneratorPtr FieldData::getBndryGenerator(BndryLoc location) {
-  auto it = bndry_generator.find(location);
-  if (it == bndry_generator.end()) {
-    return nullptr;
+  if (const auto it = bndry_generator.find(location); it != bndry_generator.end()) {
+    return it->second;
   }
 
-  return it->second;
+  return nullptr;
 }
 
 Mesh* FieldData::getMesh() const {

src/field/field_factory.cxx

@@ -301,8 +301,7 @@ Field3D FieldFactory::create3D(FieldGeneratorPtr gen, Mesh* localmesh, CELL_LOC
   };
 
   if (transform_from_field_aligned) {
-    auto coords = result.getCoordinates();
-    if (coords == nullptr) {
+    if (auto coords = result.getCoordinates(); coords == nullptr) {
       // Should not lead to issues. If called from the coordinates
       // constructor, then this is expected, and the result will be
       // transformed. Otherwise, if the field is used untransformed,
@@ -352,8 +351,7 @@ FieldPerp FieldFactory::createPerp(FieldGeneratorPtr gen, Mesh* localmesh, CELL_
   };
 
   if (transform_from_field_aligned) {
-    auto coords = result.getCoordinates();
-    if (coords == nullptr) {
+    if (auto coords = result.getCoordinates(); coords == nullptr) {
       // Should not lead to issues. If called from the coordinates
       // constructor, then this is expected, and the result will be
       // transformed. Otherwise, if the field is used untransformed,
@@ -376,8 +374,7 @@ const Options* FieldFactory::findOption(const Options* opt, const std::string& n
   const Options* result = opt;
 
   // Check if name contains a section separator ':'
-  size_t pos = name.find(':');
-  if (pos == std::string::npos) {
+  if (auto pos = name.find(':'); pos == std::string::npos) {
     // No separator. Try this section, and then go through parents
 
     while (!result->isSet(name)) {
@@ -517,8 +514,7 @@ FieldGeneratorPtr FieldFactory::parse(const std::string& input,
     key = opt->str() + key; // Include options context in key
   }
 
-  auto it = cache.find(key);
-  if (it != cache.end()) {
+  if (auto it = cache.find(key); it != cache.end()) {
     return it->second;
   }
 

src/mesh/coordinates_accessor.cxx

@@ -21,8 +21,7 @@ CoordinatesAccessor::CoordinatesAccessor(const Coordinates* coords) {
   Mesh* mesh = coords->dx.getMesh();
   mesh_nz = mesh->LocalNz;
 
-  auto search = coords_store.find(coords);
-  if (search != coords_store.end()) {
+  if (const auto search = coords_store.find(coords); search != coords_store.end()) {
     // Found, so get the pointer to the data
     data = search->second.begin();
     return;