Re: [lmi] assorted warnings & compilation fixes

[Greg Chicares]

On 2012-05-25 11:21Z, Vaclav Slavik wrote:
> here are some fixes for warnings (and one compilation error) I recently
> encountered:

I committed the other two, but this one gives me pause:

> (1) This fixes a warning shown by Clang++. I agree with the compiler
>     that it's easier on the human reader to use parenthesis here:
> 
> diff --git a/value_cast.hpp b/value_cast.hpp
> index 807340d..f26834f 100644
> --- a/value_cast.hpp
> +++ b/value_cast.hpp
> @@ -202,8 +202,8 @@ struct value_cast_choice
>      enum
>          {
>          one_numeric_one_string =
> -                boost::is_arithmetic<From>::value && is_string<To  >::value
> -            ||  boost::is_arithmetic<To  >::value && is_string<From>::value
> +                (boost::is_arithmetic<From>::value && is_string<To  >::value)
> +            ||  (boost::is_arithmetic<To  >::value && is_string<From>::value)
>          };

I think of AND as multiplicative, and OR as additive, and I generally
wouldn't parenthesize (a*b)+c . OTOH, '||' and '&&' have equal precedence
in the shell; furthermore, '+' and '*' don't do short-circuit evaluation;
so parentheses here aren't terribly objectionable, either, though I think
the layout guides the reader to the correct interpretation in this case.
I wouldn't mind changing this practice and writing superfluous parentheses,
but I'd rather not introduce inconsistency by changing only one occurrence.
Consider, e.g.:

contains.hpp:
#if defined __BORLANDC__ || defined __COMO_VERSION__ && __COMO_VERSION__ <= 4303

mvc_controller.cpp:
    if(checkbox || !control_is_enumerative && !datum)

zero.cpp:
            if
                (   bias_none   == bias
                ||  bias_lower  == bias && fb <= 0.0
                ||  bias_higher == bias && 0.0 <= fb
                )

Does Clang++ have a way of detecting similar instances, such as those?
Alternatively, does it have a convenient way of suppressing this warning?
Is Clang++ potentially valuable to us for other reasons?