[boost] [lexical_cast][math] can't unconditionally call math::changesign with long double

lexical_cast is using math::changesign with long double regardless of whether BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS is defined or not. This is causing Boost.Test build problems (see here http://tinyurl.com/af5453h). I'm pretty sure this is a bug in lexical_cast, so I've opened a ticket: https://svn.boost.org/trac/boost/ticket/8162 I've assigned it to the last person to touch lexical_cast.hpp. Apologies if that's not right. There is no entry for lexical_cast in libs/maintainers.txt. -- Eric Niebler Boost.org http://www.boost.org