See https://github.com/NVIDIA/stdexec/blob/16076a81efa4477513e6ede9c2741fd034ecef99/include/stdexec/__detail/__bulk.hpp#L100.
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#include <bulk.hpp>
template<typename Data>
{ data.__pol_ } -> std::same_as<const stdexec::__bulk::__policy_wrapper<stdexec::parallel_policy>&>;
}
See https://github.com/NVIDIA/stdexec/blob/16076a81efa4477513e6ede9c2741fd034ecef99/include/stdexec/_...