🐛 fix: msvc flag

Author: SigureMo

build.py

@@ -1,3 +1,4 @@
+from functools import partial
 from typing import Any
 
 from Cython.Build import cythonize
@@ -9,16 +10,41 @@
         "demo.core",
         sources=["lib/core.pyx", "lib/libcore.cpp"],
         language="c++",
-        extra_compile_args=["-std=c++17"],
-        extra_link_args=["-std=c++17"],
     ),
 ]
 
 
+class BuildExt(build_ext):
+
+    compiler_flags = {
+        "msvc": "/std:{std}",
+        "unix": "-std={std}",
+    }
+
+    def __init__(self, *args: Any, std: str = "", **kwargs: Any):
+        self.std = std
+        super().__init__(*args, **kwargs)
+
+    def build_extensions(self):
+        if self.std:
+            std_options = [self.compiler_flags[self.compiler.compiler_type].format(std=self.std)]
+        else:
+            std_options = []
+
+        for ext in self.extensions:
+            ext.extra_compile_args += std_options
+            ext.extra_link_args += std_options
+
+        super().build_extensions()
+
+
+Cpp20BuildExt = partial(BuildExt, std="c++20")
+
+
 def build(setup_kwargs: dict[str, Any]):
     setup_kwargs.update(
         {
             "ext_modules": cythonize(ext_modules),
-            "cmdclass": {"build_ext": build_ext},
+            "cmdclass": {"build_ext": Cpp20BuildExt},
         }
     )