Last week, we were considering using the parameter library in some client software that demands high performance (they are doing massively parallel statistical analysis), so I sat with Matthias Troyer, an expert in high-performance C++, and developed the test that's now checked in at libs/parameter/test/efficiency.cpp. The test was carefully designed to avoid deceptive effects due to dead code elimination, constant propagation, and CPU architecture, and the process of developing it was highly instructive to me personally. We left lots of comments in the code so I'd be able to remember the issuse involved. I recommend reviewing it for anyone interested in how to measure abstraction penalty. One set of results is checked in at libs/parameter/test/timings.txt, and are reproduced below. As you can see, at least on that platform, you don't need to worry about Boost.Parameter slowing your code down; it might even speed your code up! We'd be very interested in seeing results produced with other compilers and/or platforms at the highest optimization levels. ----------------- Test #1 ---------------- Testers: Matthias Troyer, Michael Gauckler, David Abrahams Date: 2005-09-09 Compiler: Cygwin g++-4.0.0 Command lines: g++ -c -o efficiency.o -ftemplate-depth-100 -funroll-loops \ -O3 -finline-functions -Wno-inline -DNDEBUG efficiency.cpp g++ -o efficiency.exe efficiency.o -Wl,--strip-all efficiency && efficiency && efficiency Machine: Dell Inspiron 9300 Intel(R) Pentium(R) M processor 2.00GHz Running on 230 volts AC power Timings: Run #1 results discarded per standard practice Run #2 plain time: 0.75 named parameter time: 0.734 Run #3 plain time: 0.781 named parameter time: 0.766 ----------------------------------------- -- Dave Abrahams Boost Consulting www.boost-consulting.com