[boost] Re: call_traits aka parameter_traits

From: Howard Hinnant (hinnant_at_[hidden])
Date: 1999-11-28 16:57:51

Beman Dawes wrote on 11/28/99 4:32 PM

>call_traits<> and empty_member<> have been added to an experimental
>version of utility.hpp:
>
>
>http://www.boost.org/libs/experimental/utility.hpp
>http://www.boost.org/libs/experimental/call_traits_test.hpp
>
>The test program works under GCC 2.95.2, Metrowerks CodeWarrior 5.2,
>and MS VC++ 6.0 SP3.
>
>Comments appreciated!

I find it a little confusing that:

single<UDT>        constructing @unnamed@::UDT by-reference
single<UDT&>       constructing @unnamed@::UDT by-value
single<const UDT&> constructing @unnamed@::UDT by-value

I can see the logic, but my knee jerk reaction is that the last two are 
passed by reference, not by value.  Should by_value = false in the T& 
specialization?

single<UDT>        constructing @unnamed@::UDT by-reference
single<UDT&>       constructing @unnamed@::UDT by-reference
single<const UDT&> constructing @unnamed@::UDT by-reference

-Howard