Re: [boost] [units] gcc warnings

Subject: Re: [boost] [units] gcc warnings
From: Jeff Flinn (TriumphSprint2000_at_[hidden])
Date: 2010-06-15 07:56:59

Stewart, Robert wrote:
> Jürgen Hunold wrote:
>> I start using Boost.Units for a new project and found some
>> annyoing warnings when compiling with "-Wall -Wextra" and
>> "-Wconversion"
> 
> Don't do that and you won't get those warnings!  (Just kidding.)
> 
>> /home/hunold/src/devel/boost/boost/units/io.hpp: In function 'int
>> boost::units::get_flags(std::ios_base&, int)':
>> /home/hunold/src/devel/boost/boost/units/io.hpp:163: warning:
>> conversion to
>> 'int' from 'long int' may alter its value [-Wconversion]
>>
>> Patch using an explicit static_cast<int> for the return value
>> attached.
> 
> Do you know that the long int value can never exceed the range of int?  If not, the static_cast will simply mask the problem.  It would be better to check against std::numeric_limits<int>::max() before casting, and resort to an exception if the range is exceeded.

IIRC, that's boost::numeric_cast's purpose.

Jeff