Is there any performance difference between BOOST_FOREACH_PAIR(K const &key, V &val, map) { } and BOOST_FOREACH(Map::reference ref, map) { } ? On Tue, Sep 15, 2009 at 7:04 AM, Chris Purcell <chris.purcell.39@gmail.com>wrote:
2009/9/14 Markus Werle <numerical.simulation@web.de>:
Chris Purcell <chris.purcell.39 <at> gmail.com> writes:
std::map<int, int> my_map; BOOST_FOREACH_PAIR(int key, int value, my_map) std::cout << key << " : " << value << "\n";
Can you provide a link to the code? I'd like to test it.
I haven't got a web page to put it, but it's pretty small, so I've put it inline sans newlines. It's alpha-quality only.
#define BOOST_FOREACH_PAIR(KEY, VALUE, COL) BOOST_FOREACH_PREAMBLE() if (boost::foreach_detail_::auto_any_t BOOST_FOREACH_ID(_foreach_col) = BOOST_FOREACH_CONTAIN(COL)) {} else if (boost::foreach_detail_::auto_any_t BOOST_FOREACH_ID(_foreach_cur) = BOOST_FOREACH_BEGIN(COL)) {} else if (boost::foreach_detail_::auto_any_t BOOST_FOREACH_ID(_foreach_end) = BOOST_FOREACH_END(COL)) {} else for (bool BOOST_FOREACH_ID(_foreach_continue) = true, BOOST_FOREACH_ID(_foreach_key_loop) = true; BOOST_FOREACH_ID(_foreach_continue) && !BOOST_FOREACH_DONE(COL); BOOST_FOREACH_ID(_foreach_continue) ? BOOST_FOREACH_NEXT(COL) : (void)0) if (boost::foreach_detail_::set_false(BOOST_FOREACH_ID(_foreach_continue))) {} else if (boost::foreach_detail_::set_false(BOOST_FOREACH_ID(_foreach_key_loop))) {} else for (KEY = BOOST_FOREACH_DEREF(COL).first; !BOOST_FOREACH_ID(_foreach_key_loop); BOOST_FOREACH_ID(_foreach_key_loop) = true) for (VALUE = BOOST_FOREACH_DEREF(COL).second; !BOOST_FOREACH_ID(_foreach_continue); BOOST_FOREACH_ID(_foreach_continue) = true)
I don't know if there are any changes to the library on subversion trunk; the above works with Boost 1.40.0. Any line breaks have been added en-route.
Cheers, Chris _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost