Thrust only implements the mismatch overloads taking an unbounded second range: InputIt1 first1, InputIt1 last1, InputIt2 first2. However, since C++14 there are also overloads where we can specify the end of the second range: InputIt1 first1, InputIt1 last1, InputIt2 first2, InputIt2 last2. We should provide these overloads. See also: https://en.cppreference.com/w/cpp/algorithm/mismatch.