Re: [boost] [units] warnings under msvc

From: John Maddock (john_at_[hidden])
Date: 2007-02-14 07:28:20

Michael Marcin wrote:
> Paul A Bristow wrote:
>>> From experience producing code that compiles cleanly MSVC 8.0 at
>>> level 4,
>>
>> may I suggest that none of these are helpful warnings and should be
>> suppressed:
>>
>> #  pragma warning(disable: 4127) // conditional expression is
>> constant
>
> Really?
>
> I would tend to take that as a sign that the code in question could be
> written differently to avoid the conditional, perhaps using SFINAE
> overloads if its controlled by a template parameter's value.

Depends, the main cases I have are things like:

if(std::numeric_limits<T>::has_infinity)
{
  // case A
}
else
{
  // case B
}

Where cases A and B are tiny one-liners that are a small part of the overall 
function.  You could factor it out, but it makes the code more rather than 
less obfuscated.

My gut feeling is that sometimes it's just not worth the hassle to refactor 
code like this, even though I was once rather obsessive about doing so!

I also have a few cases where there is something like:

if(foo<T>() > 0)

where sometimes foo<T>() gets inline-expanded to an integral constant 
expression, and sometimes not (depends on T), so the warning may only appear 
for certain compilers, with certain types T, for certain optimisation 
settings :-(

John.