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Subject: Re: [boost] [units] gcc warnings
From: Emil Dotchevski (emil_at_[hidden])
Date: 2010-06-15 12:43:36

On Tue, Jun 15, 2010 at 3:55 AM, Stewart, Robert <Robert.Stewart_at_[hidden]> 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.

With or without the static_cast, if the long int value exceeds the
range of an int you're screwed. The only difference the cast makes is
that you won't get the warning.

The problem with using casts to silence warnings is that silencing the
warning is a side effect of altering of the behavior of what is
usually a correct program.

Emil Dotchevski
Reverge Studios, Inc.

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