Specifically we turned `mean`, `classify_outliers`, `jackknife`,
into concrete functions that take only `const_iterator` from vecs,
instead of generic iterators over anything.
I also changed `resample` to take `const_iterator` instead of
plain `iterator`, and similar for `standard_deviation`, and
`analyse_samples`.
* Split out BenchmarkInfo and BenchmarkStats to their own header
* Outline BenchmarkStats<> declaration to separate header
* Split out TestRunInfo into its own header
These changes let us remove the large `interfaces_reporter.hpp`
include from `benchmark.hpp`, and replace it with
`interfaces_capture.hpp` in `run_context.hpp`.
I also cleaned out `interfaces_repoter.hpp` from reporter headers
that depend on `reporter_common_base.hpp`. This will not change
anything in the actual inclusion set, but makes it logically
more consistent.
To keep the compilation firewall effect, the implementations
are hidden behind a PIMPL. In this case it is probably not
worth it, but we can inline it later if needed.
I do not know if checking the tracker name or the tracker's file
part of the location first would provide better results, but
in the common case, the line part of the location check should be
rather unique, because different `SECTION`s will have different
source lines where they are defined.
I also propagated this same check into `ITracker::findChild`,
because this significantly improves performance of section tracking
in Debug builds -> 10% in macro benchmark heavily focused on section
tracking. In Release build there is usually no difference, because
the inliner will inline `NameAndLoc::operator==` into `findChild`,
and then eliminate the redundant check. (If the inliner decides
against, then this still improves the performance on average).
`NameAndLocationRef` is pretty large type, so even in release build,
it is unlikely to be passed in registers. In addition to the fact
that some platforms currently do not allow passing even small types
in register (Windows ABI!!), it is better to pass it as a ref,
effectively passing around a pointer.
