Fix for "variable set but not used" warning with GCC >= 4.6

[zeratul976@…]

GCC >= 4.6 gives the following "variable set but not used" warnings for code in boost/date_time/format_date_parser.hpp:

../../lib/boost/boost/date_time/format_date_parser.hpp:479:11: warning:
    variable 'current_char' set but not used [-Wunused-but-set-variable]
../../lib/boost/boost/date_time/format_date_parser.hpp:584:11: warning:
    variable 'current_char' set but not used [-Wunused-but-set-variable]
../../lib/boost/boost/date_time/format_date_parser.hpp:677:11: warning:
    variable 'current_char' set but not used [-Wunused-but-set-variable]

The warnings are triggered by any code that instantiates the format_date_parser class, for example:

#include <sstream>
#include <boost/date_time/posix_time/posix_time.hpp>

int main()
{
    std::stringstream ss;
    boost::posix_time::ptime p;
    ss >> p;
}

Looking at the code, I can see that the 'current_char' variable is indeed set but never used in those functions.

The attached patch fixes the warnings by removing the 'current_char' variable from those functions.

[zeratul976@…]

patch that fixes the warnings

[Marshall Clow]

(In [80699]) Remove unused variable; Refs #7342 Refs #6136

[Marshall Clow]

(In [80797]) Merge bug fixes to release; Fixes #5550 Fixes #6136 Fixes #6513 Fixes #7111 Fixes #7112 Fixes #7113 Fixes #7342 Fixes #7426

[Johan Lundberg <lundberj@…>]

I would like to bring attention to this bug. I'm surprised that although it was fixed nine months ago, the change did not make it to 1.54 beta1 or to trunk. Is that an oversight?

Example of what I expected was the removal of the unused variable current_char:

​https://svn.boost.org/trac/boost/changeset/80797#file5

but what is found in 1.54 beta1 looks like this

​http://svn.boost.org/svn/boost/trunk/boost/date_time/format_date_parser.hpp

[Johan Lundberg <lundberj@…>]

To clarify (also selecting 1.54.0 as Version) that the issue is still found in

• 1.54 beta1
• trunk
• release branch

​http://svn.boost.org/svn/boost/branches/release/boost/date_time/format_date_parser.hpp ​http://svn.boost.org/svn/boost/trunk/boost/date_time/format_date_parser.hpp

[Marshall Clow]

I have no explanation for this.

I made these changes; see [80699] (trunk) and [80797] (release), but the files in SVN no longer contain those changes.

[Marshall Clow]

(In [84834]) Fixed more compiler warnings; Refs #6136

[Marshall Clow]

(In [84860]) Merge bug fixes to release. Fixes #6136. Fixes #5550