Re: [Boost-users] logical operators in lambda

Subject: Re: [Boost-users] logical operators in lambda
From: Conoscenza Silente (abruzzoforteegentile_at_[hidden])
Date: 2010-04-08 09:17:04

...auch..I figure it out
..I was missing the top header #include "boost/lambda/lambda.hpp"...
Thanks again
Mn

On Thu, Apr 8, 2010 at 2:47 PM, Conoscenza Silente <
abruzzoforteegentile_at_[hidden]> wrote:

> Hi Steven
> sorry to bother you again..but the code doesn't work...I didn't try it
> yesterday when you replied..sorrry for this!
> I read in the documentation that we need some short-circuiting for logical
> operators..
>
> On Wed, Apr 7, 2010 at 5:22 PM, Steven Watanabe <watanabesj_at_[hidden]>wrote:
>
>> 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
>>
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>>
>
>