AMDG er wrote:

If say vector_type has N elements and predicate is true only for one of them.

O(N)?

typedef filter_view view_t

O(1)?

view_t view(v);

both of these should incur O(1) template instantiations. Iterating over the sequence requires O(N) template instantiations but the runtime complexity may be O(1) depending on compiler optimizations. In Christ, Steven Watanabe