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 08:47:02

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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