Re: [Boost-bugs] [Boost C++ Libraries] #10924: conversion of float/double to cpp_dec_float_100 causes hang before main() on cygwin

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #10924: conversion of float/double to cpp_dec_float_100 causes hang before main() on cygwin
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2015-02-06 18:38:01

#10924: conversion of float/double to cpp_dec_float_100 causes hang before main()
on cygwin
-------------------------------+-----------------------------------
  Reporter:  anonymous         |      Owner:  johnmaddock
      Type:  Bugs              |     Status:  closed
 Milestone:  To Be Determined  |  Component:  multiprecision
   Version:  Boost 1.57.0      |   Severity:  Problem
Resolution:  fixed             |   Keywords:  cygwin multiprecision
-------------------------------+-----------------------------------
Changes (by johnmaddock):

 * status:  new => closed
 * resolution:   => fixed

Comment:

 Turns out this is quite a pervasive issue - if there are no long double
 math functions (as on cygwin) then a call such as:

 stdlibfunc(BIG_VALUE)

 may simply return infinity as BIG_VALUE gets silently converted to double
 inside "stdlibfunc".  In this particular case it's frexp/ldexp that are
 basically returning nonsense and breaking the program invariants.

 Simplistic fix in
 https://github.com/boostorg/multiprecision/commit/4340817fd818b80df2295060eafdf79549d88683

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/10924#comment:3>
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