Does not compile in GCC-4.9.2

[federeghe]

Hi :)

as title,

log:

modules/systems/pc.cc: In member function 'Optional<SI::Speed> PerformanceComputer::get_stall_ias(const SI::Angle&) const':
modules/systems/pc.cc:353:11: error: could not convert 'nullptr' from 'std::nullptr_t' to 'Optional<SI::Speed> {aka boost::optional<SI::Speed>}'
    return nullptr;
           ^
modules/systems/pc.cc:356:10: error: could not convert 'nullptr' from 'std::nullptr_t' to 'Optional<SI::Speed> {aka boost::optional<SI::Speed>}'
   return nullptr;
          ^
modules/systems/pc.cc: In member function 'Optional<SI::Speed> PerformanceComputer::tas_to_ias(const SI::Speed&) const':
modules/systems/pc.cc:372:10: error: could not convert 'nullptr' from 'std::nullptr_t' to 'Optional<SI::Speed> {aka boost::optional<SI::Speed>}'
   return nullptr;

[mcvsama]

Also fails in 5.1.0. I wonder how it worked before, did boost::optional change? Whatever.

[mcvsama]

Fixed in 876cccc. Thanks for bug report. :-)

By the way, you might encounter an internal compiler error in your or some newer version of g++, namely this: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66320