[boost] FW: [Lambda] find_if + vector of arrays

From: Sohail Somani (s.somani_at_[hidden])
Date: 2006-07-31 11:49:12

Hi,

I'm forwarding this here as I didn't get a reply on the users list. 

> -----Original Message-----
> From: Sohail Somani 
> Sent: Tuesday, July 25, 2006 2:19 PM
> To: 'boost-users_at_[hidden]'
> Subject: [Lambda] find_if + vector of arrays
> 
> Hi,
> 
> Why can't lambda figure out the return type of operator[] for 
> array? Does it know about vectors? I know I can fix the 
> compile error by using bl::ret<double>(bl::_1[0])... But for 
> obvious reasons, I'd much rather not!
> 
> #include <vector>
> #include <algorithm>
> 
> #include <boost/array.hpp>
> #include <boost/lambda/lambda.hpp>
> 
> int main()
> {
>     namespace bl=boost::lambda;
>     using std::vector;
>     using boost::array;
> 
>     array<double,3> cpy = {1};
>     vector<vector<double> > a(10,vector<double>(3,1));
>     vector<array<double,3> > b(10,cpy);
> 
>     std::find_if(a.begin(),a.end(),bl::_1[0]==5);
>     std::find_if(b.begin(),b.end(),bl::_1[0]==5);
> }
> 
> Thanks!
> 
> Sohail
>