Initial commit: Modular Clang C++ Nix environment and problem files

nix/default.nix

@@ -0,0 +1,9 @@
+{ pkgs, treefmt-nix, llvmVersion }:
+let
+  treefmt = import ./treefmt.nix { inherit pkgs treefmt-nix; };
+  devShell = import ./devshells/default.nix { inherit pkgs llvmVersion; };
+in
+{
+  inherit devShell;
+  formatter = treefmt.config.build.wrapper;
+}

nix/devshells/default.nix

@@ -0,0 +1,38 @@
+{ pkgs, llvmVersion }:
+let
+  # Select the correct LLVM/Clang version
+  llvmPackages = pkgs."llvmPackages_${llvmVersion}";
+in
+pkgs.mkShell {
+  name = "clang-cpp-shell";
+
+  # Native dependencies (e.g., compilers, build tools)
+  nativeBuildInputs = with pkgs; [
+    # Compiler and core tools
+    llvmPackages.clang
+    llvmPackages.lld
+    llvmPackages.bintools
+    
+    # Language-specific tools
+    llvmPackages.clang-tools # Includes clang-format, clang-tidy
+    cmake
+    ninja
+    gdb
+    valgrind
+    nixpkgs-fmt
+  ];
+
+  # Runtime dependencies (e.g., shared libraries)
+  buildInputs = with pkgs; [
+    # Common libraries (example)
+    libcxx
+    boost
+  ];
+
+  # Environment variables
+  shellHook = ''
+    export CC=clang
+    export CXX=clang++
+    echo "Clang version: $(${llvmPackages.clang}/bin/clang --version | head -n 1)"
+  '';
+}

nix/treefmt.nix

@@ -0,0 +1,16 @@
+{ pkgs, treefmt-nix }:
+treefmt-nix.lib.evalModule pkgs {
+  projectRootFile = "flake.nix";
+  
+  # Configure individual formatters
+  programs = {
+    # Nix formatter
+    nixpkgs-fmt.enable = true;
+    
+    # C++ formatter
+    clang-format.enable = true;
+  };
+
+  # Optional settings
+  settings.formatter.clang-format.includes = [ "*.cpp" "*.h" "*.hpp" "*.c" ];
+}