Re: [boost] Result of boost::split against empty string changed in post-1.45 release

Subject: Re: [boost] Result of boost::split against empty string changed in post-1.45 release
From: Pavol Droba (droba_at_[hidden])
Date: 2012-06-11 14:09:00

On Mon, 11 Jun 2012 16:58:40 +0200, Mateusz Loskot <mateusz_at_[hidden]>  
wrote:

> Hi,
>
> I have a simple program runs boost::split against empty string.
> I'm testing with Boost 1.45 and later versions like 1.46 or 1.49.
> As stated in the // comment below, there is difference in behaviour
> depending on the Boost version:
>
> // https://gist.github.com/2910461
> #include <cassert>
> #include <string>
> #include <vector>
> #include <boost/algorithm/string/split.hpp>
> #include <boost/algorithm/string/classification.hpp>
>
> int main(int argc, wchar_t* argv[])
> {
>     std::wstring s;
>     std::vector<std::wstring> a;
>
>     assert(s.empty());
>     boost::split(a, s, boost::is_any_of(L", "),  
> boost::token_compress_on);
>     // Boost 1.45:  true
>     // Boost 1.46+: false
>     //   Assertion failed: s.empty() == a.empty(), file
> boost_split_empty_string.cpp, line 16
>     assert(s.empty() == a.empty());
>     return 0;
> }
>
> IMHO, the behaviour exposed in newer versions is a bug.
> Could anyone shed light on what happened in post-1.46?
>

Hi,

Please search the boos archives. There was an extensive discussion about  
this
particular issue.

The current behavior is consistent with the assertion that split always
returns n+1 tokens where n is number of separators in the input string.

Best Regards,
Pavol.