On systems where std::chrono::steady_clock::period is not std::nano, benchmark tests fail to compile due to trying to convert analysis.samples from a vector of duration<double, clock::period> to a vector of std::chrono::duration<double, std::nano>.
Its intent was to show which headers are expected to be useable by
Catch2's users, and to enforce their inclusion in the single header
distribution at the right place.
Given the new library model, the second use case is not needed and
the first one is better served with documentation and physical file
layout.
Now that Catch2 is a proper library, we can always build the full
library (comparatively minor slowdown) and the user can avoid
including benchmarking headers to avoid the compilation slowdown.
The use we previously used the polyfill or naked new is that we
supported C++11, which did not yet have `std::make_unique`. However,
with the move to C++14 as the minimum, `std::make_unique` can be
expected to be always available.
Because some of the tooling used by Catch2 does not properly support
version postfixes, such as `preview-1`, we will report the
in-development version is `v3.0.0`, and the first real release will
have to be `v3.0.1`.
Closes#1824
Now that the recommended distribution and usage method is proper
library, users can just avoid including the matcher headers to get
basically the same effect.
