Fix formatting issue and enable clang-format check

Author: ahojukka5

flake.nix

@@ -149,9 +149,14 @@
             buildInputs = [ pkgs.clang-tools_17 ];
             src = ./.;
           } ''
-            # TODO: Uncomment the following lines to check the code format.
-            # cp -r $src/* .
-            # clang-format --dry-run --Werror $(find ./apps ./include ./examples ./tests ./docs -name '*.hpp' -o -name '*.cpp')
+            cp -r $src/. .
+
+            # Find only real source files (*.cpp, *.hpp) in apps, include, examples, and tests
+            files=$(find ./apps ./include ./examples ./tests ./docs \( -name '*.hpp' -o -name '*.cpp' \))
+
+            # Run clang-format check
+            clang-format --dry-run --Werror $files
+
             touch $out
           '';
 

include/openpfc/fft.hpp

@@ -35,7 +35,7 @@ class FFT {
       heffte::plan_options plan_options = heffte::default_options<heffte::backend::fftw>())
       : m_decomposition(decomposition),
         m_fft({m_decomposition.inbox, m_decomposition.outbox, m_decomposition.r2c_direction, comm, plan_options}),
-        m_wrk(std::vector<std::complex<double>>(m_fft.size_workspace())) {};
+        m_wrk(std::vector<std::complex<double>>(m_fft.size_workspace())){};
 
   /**
    * @brief Performs the forward FFT transformation.