[boost] [config] How does math_info report signalling NaN values?

How does math_info report signalling NaN values? I am trying to find regressions in a certain compiler config, and it fails math_info test as soon as it tries to evaluate the signalling NaN values - as it duly generates an unhandled signal and terminates. None of the other platforms appear to have this problem, or I can't see any obvious workaround if they do, yet the behaviour makes sense to me. Am I missing something obvious? -- AlisdairM