Re: [Boost-users] Runtime identity

Subject: Re: [Boost-users] Runtime identity
From: John B. Turpish (jbturp_at_[hidden])
Date: 2010-11-30 18:48:11

On Tue, Nov 30, 2010 at 10:06 AM, Robert Jones <robertgbjones_at_[hidden]> wrote:
> Something that just returns it's single argument, eg.,
>
> template <typename T> T identity( T t ) { return t; }
...
> (I need this because I need to pass a function object which simply returns
> an
> object I already have - maybe I've missed a more obvious method?)

The way you wrote it, wouldn't that actually return a temporary that
is a copy of the object you already have? (rather than a const T& or
something)

I think the unary operator+() has similar semantics by convention, but
you'd have to consider the types being used and whether they define it
at all.