Add SimpleArray::as_span() and as_mdspan<N>()

.github/actions/setup_linux/action.yml

@@ -89,16 +89,17 @@ runs:
         sudo ln -fs "$(which clang-tidy-22)" "/usr/local/bin/clang-tidy"
         echo "::endgroup::"
 
-    - name: Install and configure gcc-14
+    - name: Install and configure gcc-16
       shell: bash
       run: |
-        echo "::group::Install and configure gcc-14"
+        echo "::group::Install and configure gcc-16"
+        sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test
         sudo apt-get -qqy update
-        sudo apt-get -qy install gcc-14 g++-14
-        sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-14 100
-        sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-14 100
-        sudo update-alternatives --install /usr/bin/cc cc /usr/bin/gcc-14 100
-        sudo update-alternatives --install /usr/bin/c++ c++ /usr/bin/g++-14 100
+        sudo apt-get -qy install gcc-16 g++-16
+        sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-16 100
+        sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-16 100
+        sudo update-alternatives --install /usr/bin/cc cc /usr/bin/gcc-16 100
+        sudo update-alternatives --install /usr/bin/c++ c++ /usr/bin/g++-16 100
         echo "::endgroup::"
 
     - name: install qt

cpp/modmesh/buffer/SimpleArray.hpp

@@ -38,11 +38,14 @@
 #include <modmesh/toggle/RadixTree.hpp>
 
 #include <algorithm>
+#include <array>
 #include <concepts>
 #include <format>
 #include <functional>
 #include <limits>
+#include <mdspan>
 #include <numeric>
+#include <span>
 #include <stdexcept>
 
 #ifdef _MSC_VER
@@ -1946,6 +1949,57 @@ class SimpleArray
     template <typename... Args>
     value_type * vptr(Args... args) { return m_body + buffer_offset(m_stride, args...); }
 
+    std::span<value_type> as_span()
+    {
+        if (!is_c_contiguous())
+        {
+            throw std::runtime_error("SimpleArray::as_span: array is not C-contiguous");
+        }
+        return std::span<value_type>(data(), size());
+    }
+    std::span<value_type const> as_span() const
+    {
+        if (!is_c_contiguous())
+        {
+            throw std::runtime_error("SimpleArray::as_span: array is not C-contiguous");
+        }
+        return std::span<value_type const>(data(), size());
+    }
+
+    template <size_t N>
+    std::mdspan<value_type, std::dextents<size_t, N>> as_mdspan()
+    {
+        if (ndim() != N)
+        {
+            throw std::out_of_range(
+                std::format("SimpleArray::as_mdspan: rank {} does not match ndim() {}", N, ndim()));
+        }
+        if (!is_c_contiguous())
+        {
+            throw std::runtime_error("SimpleArray::as_mdspan: array is not C-contiguous");
+        }
+        std::array<size_t, N> exts;
+        for (size_t i = 0; i < N; ++i) { exts[i] = shape(i); }
+        return std::mdspan<value_type, std::dextents<size_t, N>>(data(), exts);
+    }
+
+    template <size_t N>
+    std::mdspan<value_type const, std::dextents<size_t, N>> as_mdspan() const
+    {
+        if (ndim() != N)
+        {
+            throw std::out_of_range(
+                std::format("SimpleArray::as_mdspan: rank {} does not match ndim() {}", N, ndim()));
+        }
+        if (!is_c_contiguous())
+        {
+            throw std::runtime_error("SimpleArray::as_mdspan: array is not C-contiguous");
+        }
+        std::array<size_t, N> exts;
+        for (size_t i = 0; i < N; ++i) { exts[i] = shape(i); }
+        return std::mdspan<value_type const, std::dextents<size_t, N>>(data(), exts);
+    }
+
     /* Backdoor */
     value_type const & data(size_t it) const { return data()[it]; }
     value_type & data(size_t it) { return data()[it]; }
@@ -2423,4 +2477,4 @@ class SimpleArrayPlex
 
 } /* end namespace modmesh */
 
-/* vim: set et ts=4 sw=4: */
+// vim: set ff=unix fenc=utf8 et sw=4 ts=4 sts=4:

gtests/CMakeLists.txt

@@ -29,6 +29,7 @@ add_executable(
     test_nopython_transform.cpp
     test_nopython_rtree.cpp
     test_nopython_formatter.cpp
+    test_nopython_mdspan.cpp
     ${MODMESH_TOGGLE_SOURCES}
     ${MODMESH_BUFFER_SOURCES}
     ${MODMESH_SERIALIZATION_SOURCES}