add github workflow for test-pypi cross-OS wheel builds

Author: AlePalu

.github/workflows/testpypi-linux.yml

@@ -0,0 +1,44 @@
+name: Build Windows wheels (TestPyPI)
+
+on:
+  push:
+    tags:
+      - "v*-test*"
+
+jobs:
+  build_windows_wheels:
+    name: Build Windows wheels
+    runs-on: windows-latest
+
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          persist-credentials: false
+          submodules: recursive
+
+      - uses: actions/setup-python@v6
+        with:
+          python-version: 3.11  
+
+      - name: Install build tools
+        run: python -m pip install --upgrade pip
+      - run: python -m pip install cibuildwheel twine nanobind build
+
+      - name: Download Eigen headers
+        run: |
+          mkdir deps\eigen3
+          curl -L https://gitlab.com/libeigen/eigen/-/archive/3.4.0/eigen-3.4.0.tar.gz `
+            | tar xz -C deps\eigen3 --strip-components=1
+
+      - name: Build wheels
+        run: python -m cibuildwheel --output-dir wheelhouse
+        env:
+          CIBW_BUILD: "cp311-* cp312-* cp313-* cp314-*"
+          CIBW_ARCHS_WINDOWS: "auto"
+
+      - name: Upload to TestPyPI
+        run: |
+          twine upload --repository-url https://test.pypi.org/legacy/ wheelhouse/*
+        env:
+          TWINE_USERNAME: __token__
+          TWINE_PASSWORD: ${{ secrets.TEST_PYPI_TOKEN }}

.github/workflows/testpypi-macos.yml

@@ -568,8 +568,9 @@ class scalar_data_layer {
     template <typename T> static constexpr bool is_valid_pair_v = is_valid_pair<T>::value;  
     // moves std::tuple<Ts...> to T<Ts...>
     template <template <typename...> typename T, typename U> struct strip_tuple_into;
-    template <template <typename...> typename T, typename... Us>
-    struct strip_tuple_into<T, std::tuple<Us...>> : std::type_identity<T<Us...>> { };
+    template <template <typename...> typename T, typename... Us> struct strip_tuple_into<T, std::tuple<Us...>> {
+        using type = T<Us...>;
+    };
    public:
     template <typename T> using reference = typename data_table<T>::reference;
     template <typename T> using const_reference = typename data_table<T>::const_reference;