-----Original Message----- From: boost-users-bounces@lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Steven Watanabe Sent: Thursday, May 13, 2010 6:46 PM To: boost-users@lists.boost.org Subject: Re: [Boost-users] [Boost.Units] quantity<unit> problem with template specialisation algorithm?
AMDG
Thomas Shorrock wrote:
many thankyous to the developers of Boost.Units and Boost libraries generally, I have been using them for a few years now and this is my first difficulty.
I have been having some problems when using template specialisation (g++ 4.4.3) with Boost.Units (Boost 1_42_0). When calling a specialised template function I have found that I need to be very careful with the argument,
In short, specialised_templated_function(1.0 * boost::units::si::metre) works fine specialised_templated_function(1 * boost::units::si::metre) specialised function is not found (default tried)
1 * boost::units::si::metre returns boost::units::quantity<boost::units::si::length, int>, which doesn't match boost::units::quantity<boost::units::si::lenth, double>. You would have the same problem if you used built-in types directly.
As ever, Steven is quite right about this, but I have also plopped right into this pit myself in my first fumbles with Boost.Units. It could certain use a bit louder warning in the docs - I'm sure I won't be the last to make this mistake. Is there a reason why int isn't 'supported' (for built-in types at least)? Is it to avoid potential bloat (short, long, unsigned ..)? Or just too much hassle? Paul --- Paul A. Bristow Prizet Farmhouse Kendal, UK LA8 8AB +44 1539 561830, mobile +44 7714330204 pbristow@hetp.u-net.com