add support of dynamically sized Eigen types (#1541)

* add support of dynamically sized Eigen types

* ensure buffer bounds safety and add unit test for dynamic Eigen matrix.

* more tests and safer iterator handling

* fix duplication

* More tests

* cleaning

* Added missing resize in BEVE reading

* formatting

* improve/fix unit tests

* fix invalid return

---------

Co-authored-by: wangzhiqiang <wangzhiqiang@fscut.com>
Co-authored-by: Stephen Berry <stephenberry.developer@gmail.com>

Author: 3 people

include/glaze/ext/eigen.hpp

@@ -32,6 +32,10 @@ namespace glz
          static void op(auto& value, is_context auto&& ctx, auto&& it, auto&& end)
          {
             ++it;
+            if (it >= end) [[unlikely]] {
+               ctx.error = error_code::unexpected_end;
+               return;
+            }
             constexpr uint8_t layout = uint8_t(!T::IsRowMajor);
             if (uint8_t(*it) != layout) {
                ctx.error = error_code::syntax_error;
@@ -45,22 +49,29 @@ namespace glz
          }
       };
 
+      // A dynamic matrix in both rows and columns
       template <matrix_t T>
-         requires(T::RowsAtCompileTime < 0 || T::ColsAtCompileTime < 0)
+         requires(T::RowsAtCompileTime < 0 && T::ColsAtCompileTime < 0)
       struct from<BEVE, T>
       {
          template <auto Opts>
          static void op(auto& value, is_context auto&& ctx, auto&& it, auto&& end)
          {
             ++it;
+            if (it >= end) [[unlikely]] {
+               ctx.error = error_code::unexpected_end;
+               return;
+            }
             constexpr uint8_t layout = uint8_t(!T::IsRowMajor);
             if (uint8_t(*it) != layout) {
                ctx.error = error_code::syntax_error;
+               return;
             }
             ++it;
             std::array<Eigen::Index, 2> extents;
             detail::read<BEVE>::op<Opts>(extents, ctx, it, end);
 
+            value.resize(extents[0], extents[1]);
             std::span<typename T::Scalar> view(value.data(), extents[0] * extents[1]);
             detail::read<BEVE>::op<Opts>(view, ctx, it, end);
          }
@@ -88,8 +99,9 @@ namespace glz
          }
       };
 
+      // A dynamic matrix in both rows and columns
       template <matrix_t T>
-         requires(T::RowsAtCompileTime < 0 || T::ColsAtCompileTime < 0)
+         requires(T::RowsAtCompileTime < 0 && T::ColsAtCompileTime < 0)
       struct to<BEVE, T>
       {
          template <auto Opts>
@@ -134,6 +146,55 @@ namespace glz
             detail::to<JSON, Value>::template op<Opts>(view, ctx, b, ix);
          }
       };
+
+      // A dynamic matrix in both rows and columns
+      template <matrix_t T>
+         requires(T::RowsAtCompileTime < 0 && T::ColsAtCompileTime < 0)
+      struct to<JSON, T>
+      {
+         template <auto Opts>
+         static void op(auto&& value, is_context auto&& ctx, auto&& b, auto&& ix)
+         {
+            dump<'['>(b, ix);
+            using RowColT = std::array<Eigen::Index, 2>;
+            RowColT extents{value.rows(), value.cols()};
+            detail::to<JSON, RowColT>::template op<Opts>(extents, ctx, b, ix);
+            dump<','>(b, ix);
+
+            std::span<typename T::Scalar> view(value.data(), value.size());
+            using Value = std::remove_cvref_t<decltype(view)>;
+            detail::to<JSON, Value>::template op<Opts>(view, ctx, b, ix);
+            dump<']'>(b, ix);
+         }
+      };
+
+      // A dynamic matrix in both rows and columns
+      template <matrix_t T>
+         requires(T::RowsAtCompileTime < 0 && T::ColsAtCompileTime < 0)
+      struct from<JSON, T>
+      {
+         template <auto Opts>
+         static void op(auto& value, is_context auto&& ctx, auto&& it, auto&& end)
+         {
+            GLZ_MATCH_OPEN_BRACKET;
+            std::array<Eigen::Index, 2> extents; //NOLINT
+            detail::read<JSON>::op<Opts>(extents, ctx, it, end);
+            value.resize(extents[0], extents[1]);
+            if (*it == ',') {
+               // we have data
+               ++it;
+               if constexpr (not Opts.null_terminated) {
+                  if (it == end) [[unlikely]] {
+                     ctx.error = error_code::unexpected_end;
+                     return;
+                  }
+               }
+               std::span<typename T::Scalar> view(value.data(), extents[0] * extents[1]);
+               detail::read<JSON>::op<Opts>(view, ctx, it, end);
+            }
+            GLZ_MATCH_CLOSE_BRACKET;
+         }
+      };
    } // namespace detail
 } // namespace glaze