Daniel J. Hofmann
94af9b7f13
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
About
The Open Source Routing Machine is a high performance routing engine written in C++11 designed to run on OpenStreetMap data.
Current build status
| build config | branch | status |
|---|---|---|
| Linux | master |  |
| Linux | develop |  |
| Windows | master/develop | |
| LUAbind fork | master |  |
Building
For instructions on how to build and run OSRM, please consult the Wiki.
To quickly try OSRM use our free and daily updated online service
Documentation
See the Wiki's server API documentation as well as the library API documentation
References in publications
When using the code in a (scientific) publication, please cite
@inproceedings{luxen-vetter-2011,
author = {Luxen, Dennis and Vetter, Christian},
title = {Real-time routing with OpenStreetMap data},
booktitle = {Proceedings of the 19th ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems},
series = {GIS '11},
year = {2011},
isbn = {978-1-4503-1031-4},
location = {Chicago, Illinois},
pages = {513--516},
numpages = {4},
url = {http://doi.acm.org/10.1145/2093973.2094062},
doi = {10.1145/2093973.2094062},
acmid = {2094062},
publisher = {ACM},
address = {New York, NY, USA},
}