Re: [Boost-users] logical operators in lambda

Subject: Re: [Boost-users] logical operators in lambda
From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2010-04-07 11:22:58

AMDG

Conoscenza Silente wrote:
> I am trying to use boost::lambda using logicat operator.
> I would like to use it in a STL  std::find_if call.
>
> What I receive is always the same error
>  error: no match for ‘operator==’ in ‘boost::lambda::<unnamed>::_1 == 13’
>
> Do you know what I am doing wrong?
> Thanks
> AFG
>
> using namespace boost::assign;
>
> int main( int argc, char** argv ){
>
>     std::vector< int > v;
>     v += 12,13,14,15;
>
>     bool found_tmp = false;
>     boost::lambda::var_type< bool >::type found(
>     boost::lambda::var(found_tmp) );
>
>     std::find_if(
>         v.begin(),
>         v.end(),
>         (
>             found = ( boost::lambda::_1 == 13 ),
>             return found
>         ) );
> }
>   

Don't try to return found inside the lambda expression.

Try

bool found = std::find_if(v.begin(), v.end(), boost::lambda::_1 == 13) 
!= v.end();

In Christ,
Steven Watanabe