From: Florian Stegner <FlSt@gmx.de>
Rob Stewart wrote:
From: FlSt@gmx.de
"n_m_of" uses anti-alphabetical ordering of the letters. That rather suggests the template argument order of maximum then minimum. Perhaps changing to "x_y_of" or "a_z_of" would be better?
Hmm... i,j,k are typical letters for indexes.. After that i_of and i_j_of are good choices.
Not all ranges are random access and we're not specifying two indices. We're instead specifying a maximum and minimum count. I rather liked the "subrange" or "subset" names that Matthew Vogt suggested (though he later recanted his suggestion of "subrange"). Unfortunately, those don't suggest the min/max counts needed. It occurs to me that most of these names are suggestive of creating a subrange ("i_j_of" suggests the i'th through j'th values in the range, for example) which then participates in the comparison. That, of course, isn't what happens. Instead, we need to indicate that between the minimum and maximum number of elements, inclusive, satisfy the predicate. As Matthew mentioned, the between(1, 2).items_of(a) spelling is clear, but I find it rather long compared to subrange_of<1,2>(a) or n_m_of<1,2>. Besides, we still need a name for the resulting type that users might need to put in a variable. In my library, there are these correspondences (Florian has a different set of names): function class template template -------- ---------- all_of all_values any_of any_value each_of each_value n_of n_values n_m_of n_m_values none_of no_values one_of one_value Thus, you could write: typedef std::set<int> range_type; range_type r; // populate r; all_values<range_type> const all(all_of(r)); What about n_m_of? n_m_values<range_type> const some(between(3, 5).items_of(r)); I picked "some" as the variable name. Would "some_of" work? some_values<range_type> const some(some_of(3, 5, r)); or some_values<range_type> const some(between(3, 5).items_of(r)); "exactly" has also been suggested n_values<range_type> const n(exactly(3).items_of(r)); as an alternative to n_values<range_type> const n(n_of(3, r)); Should that actually return a "some_values?" some_values<range_type> const n(exactly(3).items_of(r)); If we use "some_values" do we need "n_of" or "n_m_of?" They're shorter, but certainly not as clear. ("all," "none," and "one" provide efficiency, so I plan to keep them.) -- Rob Stewart stewart@sig.com Software Engineer http://www.sig.com Susquehanna International Group, LLP using std::disclaimer;