Boost C++ macro argument count error

Question

In the following piece of code:

BOOST_FOREACH(std::pair<PID, bool> &itval, completedEs_) {
    allCompleted &= it->second;
}

I'm getting this error:

error: macro "BOOST_FOREACH" passed 3 arguments, but takes just 2

I'm only passing 2 arguments, what's going on?

http://stackoverflow.com/questions/716865/c-boost-any-gotchas-with-boost-foreach/716872#716872 — phooji, Mar 24 '11 at 04:05
And: http://stackoverflow.com/questions/2104208/is-it-possible-to-use-boostforeach-with-stdmap — GManNickG, Mar 24 '11 at 04:28

score 8 · Accepted Answer · answered Mar 24 '11 at 04:07

8

The first type is being parsed as two arguments since it contains a comma. As a workaround you could typedef the type:

typedef std::pair<PID, bool> PID_bool_pair;
BOOST_FOREACH( PID_bool_pair &itval, completedEs_) {
    ...
}

answered Mar 24 '11 at 04:07

Alex Deem

score 2 · Answer 2 · answered Mar 24 '11 at 04:06

2

You can't do that because of BOOST_FOREACH macro limitations, rewrite it like:

//...
typedef std::pair<PID, bool> mypair;
BOOST_FOREACH(mypair &itval, completedEs_) {
    allCompleted &= it->second;
}
//...

answered Mar 24 '11 at 04:06

Ivan G.

2 Answers2