trying to fix clang msvc issue

Author: Creamy-pie-96

CMakeLists.txt

@@ -144,6 +144,18 @@ if(PYTHONIC_ENABLE_GRAPH_VIEWER)
     target_compile_features(pythonic_graph_viewer PUBLIC cxx_std_20)
     target_compile_definitions(pythonic_graph_viewer PUBLIC PYTHONIC_ENABLE_GRAPH_VIEWER)
 
+    # Precompiled headers to speed up compilation
+    target_precompile_headers(pythonic_graph_viewer PRIVATE
+        <algorithm>
+        <stdexcept>
+        <pythonic/pythonicDispatchForwardDecls.hpp>
+        <pythonic/pythonicError.hpp>
+        <pythonic/pythonicOverflow.hpp>
+        <pythonic/pythonicPromotion.hpp>
+        <pythonic/pythonicVars.hpp>
+        <pythonic/graph_viewer.hpp>
+    )
+    
     # Use PRIVATE for external paths to avoid installation path issues
     target_include_directories(pythonic_graph_viewer
         PUBLIC

include/pythonic/pythonicDispatchDeclarations.hpp

@@ -1,3 +1,4 @@
+#pragma once
 // Generated declarations for OpTable specializations
 template<> const std::array<std::array<BinaryOpFunc, TypeTagCount>, TypeTagCount> OpTable<Add>::table;
 template<> const std::array<std::array<BinaryOpFunc, TypeTagCount>, TypeTagCount> OpTable<Sub>::table;

scripts/gen_dispatch_stubs.py

@@ -48,6 +48,7 @@
 }
 
 if len(sys.argv) > 1 and sys.argv[1] == 'declarations':
+    print("#pragma once")
     print("// Generated declarations for OpTable specializations")
     for opname, opstruct_name in op_struct_map.items():
         print(f"template<> const std::array<std::array<BinaryOpFunc, TypeTagCount>, TypeTagCount> OpTable<{opstruct_name}>::table;")