Additional constexpr tests and tests versus views::drop | views::take #4
Description
In the design section of the paper the author says this:
Should we introduce a new slice_view class?
Nope.
As stated in P2214: "slice(M, N) is equivalent to views::drop(M) | views::take(N - M), and you couldn't do much better as a first class view. range-v3 also supports a flavor that works as views::slice(M, end - N) for a special variable end, which likewise be equivalent to r | views::drop(M) | views::drop_last(N)."
This means that slice(M, N) can simply be a trivial alias of the latter two, and author believes that such a design has fully accommodated the current desires.
We should have some tests that validate the correctness of that statement.
Also some constexpr tests using static_assert to ensure constexpr is working correctly.