is_close_to function does not exist

[John Friesen <jhpfriesen@…>]

The example code for boost::math::tools::brent_find_minima (Brent_minimise_example.cpp) calls the function is_close_to. This code results in an error (Visual Studio 15.5.5) because the compiler cannot find the function. Neither can I:

#include <boost/test/floating_point_comparison.hpp>
using boost::math::fpc::is_close_to;

The following code seems to work:
template<typename FPT>
inline bool
is_close_to(FPT left, FPT right, FPT tolerance)
{

return boost::math::fpc::close_at_tolerance<FPT>(tolerance) (left, right);

}

[John Maddock]

Paul this seems to be your code. I also note that the offending example hasn't been added to the Jamfile for the examples, otherwise this would have been detected during the CI builds.

[Paul A. Bristow]

Thanks for reporting this. Clearly a mistake. Your fix sounds plausible, but I will check this out fully in due course. And add the the jamfile so that any mistakes would be found before the users do :-(

[Paul A. Bristow]

Corrected and hopefully improved this example, now checking if expected small near zero before checking if close.

o github.com:boostorg/math.git

bf57b10fe..0fe646388 develop -> develop