Cast via uintptr_t function pointer between object pointer

Author: nobu

ext/digest/digest.h

@@ -80,7 +80,8 @@ rb_digest_make_metadata(const rb_digest_metadata_t *meta)
  typedef VALUE (*wrapper_func_type)(const rb_digest_metadata_t *meta);
  static wrapper_func_type wrapper;
  if (!wrapper) {
- wrapper = (wrapper_func_type)rb_ext_resolve_symbol("digest.so", "rb_digest_wrap_metadata");
+ wrapper = (wrapper_func_type)(uintptr_t)
+ rb_ext_resolve_symbol("digest.so", "rb_digest_wrap_metadata");
  if (!wrapper) rb_raise(rb_eLoadError, "rb_digest_wrap_metadata not found");
  }
  return wrapper(meta);