deploy: c72f37a40d

features/types/index.md

@@ -79,7 +79,8 @@ template<
     class NumberFloatType = double,
     template<typename U> class AllocatorType = std::allocator,
     template<typename T, typename SFINAE = void> class JSONSerializer = adl_serializer,
-    class BinaryType = std::vector<std::uint8_t>
+    class BinaryType = std::vector<std::uint8_t>,
+    class CustomBaseClass = void
 >
 class basic_json;
 ```
@@ -106,6 +107,8 @@ using number_float_t = NumberFloatType;
 using binary_t = nlohmann::byte_container_with_subtype<BinaryType>;
 ```
 
+Not every type can be passed for these template arguments: the library uses the resulting types in ways that imply a number of requirements, for instance that `StringType` is `char`-based or that `ArrayType` is vector-like. These requirements are collected in [Template Parameter Requirements](https://json.nlohmann.me/features/types/template_parameters/index.md).
+
 ## Objects
 
 [RFC 8259](https://tools.ietf.org/html/rfc8259) describes JSON objects as follows: