concept | ranges::partial_sum_constraints = CPP_PP_CAT( CPP_PP_DEF_IMPL_IS_PAREN_, 0 )( input_iterator<I> && indirect_semigroup< projected<projected<I )( input_iterator<I> && indirect_semigroup< projected<projected<I, detail::as_value_type_t<I>>, P>, BOp> && output_iterator< O, iter_value_t< projected<projected<I, detail::as_value_type_t<I>>, P>> const &> ) |