-----Original Message----- From: boost-bounces@lists.boost.org [mailto:boost-bounces@lists.boost.org] On Behalf Of Steven Watanabe Sent: Wednesday, November 11, 2009 6:56 PM To: boost@lists.boost.org Subject: Re: [boost] Official warnings policy?
AMDG
Paul A. Bristow wrote:
Looks like the warnings occur depending on the types used in the unit tests. For example, the warning mentioned above comes from the test code:
typedef variant< short, const char* > t_var2; typedef variant< unsigned short, const char*, t_var2 > t_var5; typedef variant< unsigned short, const char*, t_var5 > t_var6;
t_var6 v6; v6 = 58;
Which looks like a legitimate warning about converting an integer (58) to a short.
Since this is expected, could the test use a static_cast to the right type?
v6 = static_cast< t_var6 >(58);
Does this quiet the warning?
Or must it be v6 = static_cast< unsigned short >(58); ?
Either way this would document that casting/converting takes place?
And perhaps users should do this too? The static_cast documents that the author has thought about this.
I'd be careful about adding a static_cast, since it changes exactly what's being tested. Part of the behavior of a class is the way it handles implicit conversions. Even conversions that generate warnings sometimes need to be tested.
You are right, as ever. But in this case, is it my ignorance of C++ or is there no way of specifying an (unsigned) short, The test wanted to use v6 = 58US; Or unsigned short int i = 58U; v6 = i; ? Or would just v6 = 58U avoid the warning? In the test, I suspect that v6 = static_cast< t_var6 >(58); was what was really wanted (or some way of getting at the first template type from the variant that is beyond my skills). Paul --- Paul A. Bristow Prizet Farmhouse Kendal, UK LA8 8AB +44 1539 561830, mobile +44 7714330204 pbristow@hetp.u-net.com