Re: [Boost-Users] REPOST: boost.bind usage

From: Peter Dimov (pdimov_at_[hidden])
Date: 2002-03-25 11:08:13

From: "Markus Schöpflin" <markus.schoepflin_at_[hidden]>
> Since my first post using the web interface seems to have been lost, I'm
trying again via email...
>
> Is it just me or is it my compiler (MSVC6SP5)? The following code gives me
an error. Whats wrong?
>
> #include <boost/bind.hpp>
> #include <functional>
>
> using boost::bind;
>
> void main()
> {
>   bind(std::greater<int>, _1, _2)(1, 2);
> }
>
> main.cpp(8) : error C2275: 'std::greater<int>' : illegal use of this type
as an expression

To make it compile, you need to:

* change std::greater<int> to std::greater<int>();
* change bind(... to bind<bool>(... since MSVC 6 cannot deduce the return
type;
* use the qualified boost::bind<bool> syntax to work around a bug in the
compiler;

and finally, use

int x = 1;
int y = 2;

boost::bind<bool>(std::greater<int>(), _1, _2)(x, y);

since bind cannot take rvalues (this is usually not a problem in real code,
just in examples.)