Various code fixes and simplifications (#3700)

* Simplifications

* Clean up

* Simplify

* More simplifications

* Fix nasty namespace code

* Format fix

* Format

* Improve docs

* Simplifications

* macos fixes

* Int type fix

Author: garth-wells

cpp/dolfinx/common/MPI.h

@@ -29,7 +29,6 @@
 /// @brief MPI support functionality
 namespace dolfinx::MPI
 {
-
 /// MPI communication tags
 enum class tag : int
 {

cpp/dolfinx/common/Scatterer.h

@@ -18,8 +18,6 @@
 #include <type_traits>
 #include <vector>
 
-using namespace dolfinx;
-
 namespace dolfinx::common
 {
 /// @brief A Scatterer supports the MPI scattering and gathering of data

cpp/dolfinx/fem/FunctionSpace.h

@@ -44,7 +44,7 @@ class FunctionSpace
   FunctionSpace(std::shared_ptr<const mesh::Mesh<geometry_type>> mesh,
                 std::shared_ptr<const FiniteElement<geometry_type>> element,
                 std::shared_ptr<const DofMap> dofmap)
-      : _mesh(mesh), _dofmaps{dofmap}, _elements{element},
+      : _mesh(mesh), _elements{element}, _dofmaps{dofmap},
         _id(boost::uuids::random_generator()()), _root_space_id(_id)
   {
     // Do nothing

cpp/dolfinx/fem/discreteoperators.h

@@ -452,7 +452,6 @@ void interpolation_matrix(const FunctionSpace<U>& V0,
   const std::size_t dim0 = space_dim0 / bs0;
   const std::size_t value_size_ref0 = e0->reference_value_size();
   const std::size_t value_size0 = V0.element()->reference_value_size();
-  const std::size_t value_size1 = V1.element()->reference_value_size();
 
   // Get geometry data
   const CoordinateElement<U>& cmap = mesh->geometry().cmap();

cpp/dolfinx/io/HDF5Interface.cpp

@@ -135,10 +135,8 @@ std::filesystem::path io::hdf5::get_filename(hid_t handle)
   if (length < 0)
     throw std::runtime_error("Failed to get HDF5 filename from handle.");
 
-  // Allocate memory
-  std::vector<char> name(length + 1);
-
   // Retrieve filename
+  std::vector<char> name(length + 1);
   if (H5Fget_name(handle, name.data(), length + 1) < 0)
     throw std::runtime_error("Failed to get HDF5 filename from handle.");
 

cpp/dolfinx/io/HDF5Interface.h

@@ -20,7 +20,6 @@
 
 namespace dolfinx::io::hdf5
 {
-
 /// C++ type to HDF5 data type
 template <typename T>
 hid_t hdf5_type()
@@ -92,10 +91,13 @@ hid_t open_dataset(hid_t handle, const std::string& path);
 std::vector<std::int64_t> get_dataset_shape(hid_t handle,
                                             const std::string& dataset_path);
 
-/// Set MPI atomicity. See
+/// Set MPI atomicity.
+///
+/// See
 /// https://support.hdfgroup.org/HDF5/doc/RM/RM_H5F.html#File-SetMpiAtomicity
 /// and
 /// https://www.open-mpi.org/doc/v2.0/man3/MPI_File_set_atomicity.3.php
+///
 /// Writes must be followed by an MPI_Barrier on the communicator before
 /// any subsequent reads are guaranteed to return the same data.
 void set_mpi_atomicity(hid_t handle, bool atomic);