* Rewrite complexity_test to use (hardcoded) manual time
This test is fundamentally flaky, because it tried to read tea leafs,
and is inherently misbehaving in CI environments,
since there are unmitigated sources of noise.
That being said, the computed Big-O also depends on the `--benchmark_min_time=`
Fixes https://github.com/google/benchmark/issues/272
* Correctly compute Big-O for manual timings. Fixes#1758.
* complexity_test: do more stuff in empty loop
* Make all empty loops be a bit longer empty
Looks like on windows, some of these tests still fail,
i guess clock precision is too small.
Recently the library added a new ranged-for variant of the KeepRunning
loop that is much faster. For this reason it should be preferred in all
new code.
Because a library, its documentation, and its tests should all embody
the best practices of using the library, this patch changes all but a
few usages of KeepRunning() into for (auto _ : state).
The remaining usages in the tests and documentation persist only
to document and test behavior that is different between the two formulations.
Also note that because the range-for loop requires C++11, the KeepRunning
variant has not been deprecated at this time.
* Make Benchmark a single header library (but not header-only)
This patch refactors benchmark into a single header, to allow
for slightly easier usage.
The initial reason for the header split was to keep C++ library
components from being included by benchmark_api.h, making that
part of the library STL agnostic. However this has since changed
and there seems to be little reason to separate the reporters from
the rest of the library.
* Fix internal_macros.h
* Remove more references to macros.h
In non-debug builds CMake automatically adds -DNDEBUG, this means
that uses of `assert` in the tests are disabled for non-debug builds.
Obviously we want these tests to run, regardless of configuration.
This patch strips -DNDEBUG during non-debug builds and adds
-UNDEBUG just to be sure.
