From: Peter Dimov (pdimov_at_[hidden])
Date: 2005-05-05 04:39:16
Beman Dawes wrote:
> "Rob Stewart" <stewart_at_[hidden]> wrote in message
>> status_flag status(path const &, int * error = 0);
>> It is simpler from an implementation standpoint, but I don't
>> think it is simpler from the caller's perspective. Since the
>> argument is defaulted, the compiler will offer no help to ensure
>> that you get and inspect the error number.
>> Returning a type with the flags and error number together means
>> that you always get the error number and can inspect it. Whether
>> you use any schemes to ensure that the caller inspects a non-zero
>> error number -- such as asserting in the destructor if an
>> "inspected" flag isn't set -- is another matter.
> That seems like a convincing argument.
if( status( p ) & file_flag ) // ...
if( status( p, &e ) & file_flag ) // ...
if( status( p ).flags & file_flag ) // ...
status_result r = status( p );
if( r.flags & file_flag ) // ...
I don't see much of a difference here.
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