If the kind moderators allow this through I promise not to send such blatantly commercial announcements to the boost developers list again (at least for awhile :-) ). <commercial> Here is contact info which can also be found at our website www.metrowerks.com: info@metrowerks.com US Mail: Metrowerks Sales Metrowerks 9801 Metric Blvd. Austin, TX 78758 Telephone: Toll Free: 800-377-5416 International: +1 512 997 4700 Fax: +1 512 997 4901 I'm personally very proud of many of the Pro 9 features which include pseudo move semantics for vector. For example you might want to try running the following demo under CodeWarrior and your 2nd favorite compiler (optimize for speed): #include <string> #include <set> #include <iostream> #include <time.h> #include <vector> int main() { std::string s(20, ' '); std::multiset<std::string> ms; for (int i = 0; i < 100; ++i) ms.insert(s); std::vector<std::multiset<std::string> > v(10000, ms); clock_t t = clock(); v.erase(v.begin()); t = clock() - t; std::cout << (double)t/CLOCKS_PER_SEC << '\n'; } Assuming your clock() function has sufficient resolution to produce reasonable results on your platform you might be interested in the results. Of course this should be old hat to Mac users (Pro 9/Mac has been out for months). Fwiw, here's what I'm getting on my Mac: [G4:~/Documents/Development/JunkMac] hinnant% ./helloworld 0.01 // CodeWarrior Pro 9 [G4:~/Documents/Development/JunkMac] hinnant% g++ -v Reading specs from /usr/libexec/gcc/darwin/ppc/3.3/specs Thread model: posix gcc version 3.3 20030304 (Apple Computer, Inc. build 1495) [G4:~/Documents/Development/JunkMac] hinnant% g++ -O4 HelloWorld.cp [G4:~/Documents/Development/JunkMac] hinnant% ./a.out 1.08 </commercial> -Howard