Re: [Boost-users] BOOST_FOREACH with Index

On Sun, Dec 13, 2009 at 7:11 PM, OvermindDL1 wrote:

On Sun, Dec 13, 2009 at 6:41 PM, Nat Goodspeed wrote:

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Eric Niebler wrote:

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   Why not:

    int index = 0;

    BOOST_FOREACH(const Foo &f, foos)     {       // ... stuff ...       ++index;     }

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What value BOOST_FOREACH has comes primarily from its ability to simplify something that's already pretty darn simple -- a plain for(;;) loop. I strongly resist any effort to make BOOST_FOREACH more complicated, unless the wins are truly significant. In this case, I don't think they are.

Maybe this shouldn't be a BOOST_FOREACH feature at all. As with Python's builtin enumerate() function, maybe what we want here is an iterator adapter that dereferences to a std::pair?

Ooo, that makes sense, as long as it can still be done quickly (ala the in index = 0; example above): BOOST_FOREACH(size_t i, const Foo &f, ENUMERATE(foos))

Or maybe: BOOST_FOREACH_ENUMERATE(size_t i, const Foo &f, foos)

Er, meant my first example to be: BOOST_FOREACH(tuple t, ENUMERATE(foos))