Re: [Boost-users] boost::function/boost::bind compilation error

Subject: Re: [Boost-users] boost::function/boost::bind compilation error
From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2009-09-05 20:35:37

AMDG

Ahmed Badran wrote:
> I was trying to use boost function/bind to bind the first argument of 
> a member function that takes two arguments, when I got into a 
> compilation error that I can't quite decipher or understand, below is 
> a sample representation of the problem, and then there's the 
> compilation error, am I doing something incorrectly here?
>
> I have tried removing the boost::mem_fn instantiation with no difference.
>
>
> #include <boost/function.hpp>
> #include <boost/bind.hpp>
> #include <boost/mem_fn.hpp>
> #include <iostream>
>
> using namespace std;
> using namespace boost;
>
> class my_class
> {
>     public:
>     void test(bool b)
>     {
>         cout << "got " << b << endl;
>     }
>     private:
> };
>
>
>
> int main()
> {
>     my_class c;
>     boost::function1<void, bool> test_fn;
>     boost::bind(&my_class::test, &c, _2);
>
>     /* causes a compilation error */
>     test_fn = boost::bind<void>(boost::mem_fn(&my_class::test), &c, _2);

Use _1 instead of _2.  The placeholder number indicates
the first argument to the function object created by bind.
You're only passing a single bool argument in, so only _1
is a valid placeholder.

In Christ,
Steven Watanabe