The `static_rtree.hpp` header included `<booost/thread.hpp>` without using
anything from this header.
Removing it showed why:
the unit test for the rtree no longer built, since it was missing symbols
for Boost's `hash_combine`, used in the unit test.
Instead of relying on `<boost/thread.hpp>` including the proper header
for `hash_combine` by chance that we only use in the unit test, do the
following:
- remove `<boost/thread.hpp>` from the rtree implementation
- add `<boost/functional/hash.hpp>` to the rtree unit test
As always, include what you use.
This caches iterators, i.e. especially the end iterator when possible.
The problem:
for (auto it = begin(seq); it != end(seq); ++it)
this has to call `end(seq)` on every iteration, since the compiler is
not able to reason about the call's site effects (to bad, huh).
Instead do it like this:
for (auto it = begin(seq), end = end(seq); it != end; ++it)
caching the end iterator.
Of course, still better would be:
for (auto&& each : seq)
if all you want is value semantics.
Why `auto&&` you may ask? Because it binds to everything and never copies!
Skim the referenced proposal (that was rejected, but nevertheless) for a
detailed explanation on range-based for loops and why `auto&&` is great.
Reference:
- http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n3853.htm
Apply `clang-modernize` (based on Clang 3.6) transformations to the
codebase while making sure to support Clang>=3.4 and GCC>=4.8.
We apply the transformations in parallel to speed up the quite
time consuming process, and use our `clang-format` style file
to automatically format the code respecting our coding conventions.
We use the following self-explanatory transformations:
* AddOverride
* LoopConvert
* PassByValue
* ReplaceAutoPtr
* UseAuto
* UseNullptr
This required a `compile_commands.json` compilation database, e.g.
ccmake .. -DCMAKE_BUILD_TYPE=Release -DCMAKE_EXPORT_COMPILE_COMMANDS=1
for CMake or check Bear for a Makefile based solution (or even Ninja).
git ls-files -x '*.cpp|*.h' | \
xargs -I{} -P $(nproc) clang-modernize -p build -final-syntax-check -format -style=file -summary -for-compilers=clang-3.4,gcc-4.8 -include . -exclude third_party {}
Boom!
References:
* http://clang.llvm.org/extra/clang-modernize.html
* http://clang.llvm.org/extra/ModernizerUsage.html
