Re: [boost] Help with boost spirit

2014-10-14 20:44 GMT+08:00 Theodore Papadopoulo < Theodore.Papadopoulo@inria.fr>:

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Sorry, this is probably a beginner question, but I'm stuck on it for quite some time.

I'm trying to write a small string like parser in which the size of the string is first given. Some thing like:

int_ >> repeat(_1)[ char_ ]

But I cannot figure out the right way of doing this. The natural:

const bool result = boost::spirit::qi::parse(it,str.end(),int_ >> repeat(_1)[ char_ ]);

fails to compile (and I tried many variations of val, etc) with no success. If I replace _1 by 10, everything works fine.

_1 doesn't makes sense here, it's only for use in semantic action, e.g. `int_[_a = _1]`. Another question is that of the associated attribute. From the

documentation, I would have expected it to be:

typedef std::pair Attribute;

but that does not work. I have managed to work around this using a second rule, using an attribute std::vector<char>(int) but then again I do not know how to pass the parameter. 10 works but _1 does not.

perhaps you need to include the Fusion header that adapts std::pair.

Any help will be appreciated. Some test code is attached, compile with: g++ -g -std=c++11 -dboost_spirit_use_phoenix_v3 Test.C. Variants are in comment.

A working version is attached. HTH