Re: [boost] [type_traits] copy constructor

Subject: Re: [boost] [type_traits] copy constructor
From: John Maddock (boost.regex_at_[hidden])
Date: 2011-09-29 06:33:48

> What's the most portable way to detect if a type T is CopyConstructible?
>
> Actually, I would need a metafunction that is true_ iff a type T has a
> const-correct copy construct:
>
> T::T( T const& other) { /* copy this T from the other T */ }
>
> (I've been looking at boost::has_trivial_copy and
> boost::has_nothrow_copy but I wanted to double check with the ML.)

There's no trait for that because we could think of no way of implementing 
it: it would basically require a "does this code compile" compiler intrinsic 
which vendors have been very reluctant to provide (read that as v. difficult 
for them to implement).

HTH, John.