Like @ref utf8proc_map, but also takes a custom_func mapping function
that is called on each codepoint in str before any other transformations
(along with a custom_data pointer that is passed through to custom_func).
The custom_func argument is ignored if it is NULL.
Like @ref utf8proc_map, but also takes a custom_func mapping function that is called on each codepoint in str before any other transformations (along with a custom_data pointer that is passed through to custom_func). The custom_func argument is ignored if it is NULL.