Fix for Clang, which has difficulty with mixed C complex numbers.

Author: BenBrock

include/binsparse/detail/cpp/array.hpp

@@ -63,6 +63,16 @@ inline array_ptr_variant_t get_typed_ptr(bsp_array_t array) {
   return {};
 }
 
+template <typename T>
+constexpr static bool is_c_complex_v =
+    std::is_same_v<std::remove_cvref_t<T>, _Complex double> ||
+    std::is_same_v<std::remove_cvref_t<T>, _Complex float>;
+
+template <typename T, typename U>
+constexpr static bool mixed_c_complex_v =
+    (is_c_complex_v<T> && !is_c_complex_v<U>) ||
+    (!is_c_complex_v<T> && is_c_complex_v<U>);
+
 } // namespace __detail
 
 } // namespace binsparse
@@ -76,7 +86,8 @@ inline void bsp_array_read(bsp_array_t array, size_t index, T& value) {
       [&](auto* ptr) {
         using U = std::remove_pointer_t<decltype(ptr)>;
 
-        if constexpr (std::is_assignable_v<T&, U>) {
+        if constexpr (std::is_convertible_v<U, T> &&
+                      !binsparse::__detail::mixed_c_complex_v<T, U>) {
           value = ptr[index];
         }
       },
@@ -92,7 +103,8 @@ inline void bsp_array_write(bsp_array_t array, size_t index, U value) {
       [&](auto* ptr) {
         using T = std::remove_pointer_t<decltype(ptr)>;
 
-        if constexpr (std::is_assignable_v<T&, U>) {
+        if constexpr (std::is_convertible_v<U, T> &&
+                      !binsparse::__detail::mixed_c_complex_v<T, U>) {
           ptr[index] = value;
         }
       },
@@ -110,7 +122,8 @@ inline void bsp_array_awrite(bsp_array_t array_0, size_t index_0,
         using T = std::remove_pointer_t<decltype(ptr_0)>;
         using U = std::remove_pointer_t<decltype(ptr_1)>;
 
-        if constexpr (std::is_assignable_v<T&, U>) {
+        if constexpr (std::is_convertible_v<U, T> &&
+                      !binsparse::__detail::mixed_c_complex_v<T, U>) {
           ptr_0[index_0] = ptr_1[index_1];
         }
       },