id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
6812,"boost::lexical_cast<float>(""."") returns 0 instead of throwing",Bruce Merry <bmerry@…>,Antony Polukhin,"The attached program reports
{{{
boost::lexical_cast<float>(""."") returns 0
}}}
when it should report an exception. According to the lexical_cast docs, lexical_cast<float>(string) is supposed to be equivalent to
 - using stream extraction, which in turn is defined in terms of
 - num_get on the numeric facet, which is defined in terms of
 - strtold in the C standard, which requires
 - ""a non-empty sequence of decimal digits, optionally containing a decimal-point character""
strtold also refers to the grammar for a floating-point literal, which is pretty clear that either the part before or the part after the decimal point has to be non-empty.
 
Compiler is MSVC 2010 SP1. I haven't messed around with locales at all so it's whatever the default is for an English install of Windows 7.

This works with Boost 1.46 under GCC 4.6 - I'm guessing because 1.46 left parsing of float strings to operator>>.",Bugs,closed,Boost 1.50.0,lexical_cast,Boost 1.48.0,Regression,fixed,,