%-----------------------------------------------------------------------------%

:- module intermod_typeclass_exist.
:- interface.

:- typeclass dynamic_block(T) where [
    some [Q] pred generate_block(T::in, Q::out) is det
].

%-----------------------------------------------------------------------------%
%-----------------------------------------------------------------------------%

:- implementation.

:- import_module int.
:- import_module list.

%-----------------------------------------------------------------------------%

:- type simple_dynamic_block
    --->    simple_dynamic_block.

:- instance dynamic_block(simple_dynamic_block) where [
    pred(generate_block/2) is do_generate_block
].

% works
% :- some [Q] pred do_generate_block(simple_dynamic_block::in, Q::out) is det.

:- pred do_generate_block(simple_dynamic_block::in, string::out) is det.

do_generate_block(simple_dynamic_block, "qqq").

%-----------------------------------------------------------------------------%
% vim: ft=mercury ts=8 sts=4 sw=4 et