Re: [Boost-users] [spirit][qi] Iteration / string iterator

Subject: Re: [Boost-users] [spirit][qi] Iteration / string iterator
From: OvermindDL1 (overminddl1_at_[hidden])
Date: 2010-10-01 22:35:38

On Fri, Oct 1, 2010 at 2:34 PM, alfC <alfredo.correa_at_[hidden]> wrote:
> can anybody explain to me why this example from the Spirit.Qi manual
> works
>
> http://www.boost.org/doc/libs/1_44_0/libs/spirit/example/qi/complex_number.cpp
>
> and when I try to use the string iterators directly I get a horrific
> compiler error? Something to do with string iterators being pointers
> or something?
>
> Â  Â  Â  Â std::string s = "(2, 3)"; Â  // < line added to example
> Â  Â  Â  Â bool r = phrase_parse(s.begin(), s.end(), //< only line
> changed in the example was (first, last)

You are using GCC, phrase_parse's first parameter must be non-const.

Visual studio can accept a const in a non-const if it is a temporary, as above.
GCC however, follows the standard, meaning that you must create an
iterator for at least the s.begin() and pass the iterator in, not a
temporary, meaning change the above lines to this:

        std::string s = "(2, 3)";   // < line added to example
        std::string::iterator iter = s.begin();
        bool r = phrase_parse(iter, s.end(), //< only line changed in
the example was (first, last)