=for apidoc Am|U32|OP_CLASS|OP *o
Return the class of the provided OP: that is, which of the *OP
structures it uses. For core ops this currently gets the information out
-of C<PL_opargs>, which does not always accurately reflect the type used.
+of C<PL_opargs>, which does not always accurately reflect the type used;
+in v5.26 onwards, see also the function C<L</op_class>> which can do a better
+job of determining the used type.
+
For custom ops the type is returned from the registration, and it is up
to the registree to ensure it is accurate. The value returned will be
one of the C<OA_>* constants from F<op.h>.