Re: [Boost-users] Converting a BOOST_FOREACH to use the new c++ 11 lambda syntax

Subject: Re: [Boost-users] Converting a BOOST_FOREACH to use the new c++ 11 lambda syntax
From: Nathan Ridge (zeratul976_at_[hidden])
Date: 2013-01-01 16:39:31

> I’m trying to convert a BOOST_FOREACH loop to use the new lambda syntax: 
>  
> I have a ptree variable declared in a class of which the foreach is  
> part. I also have a vector<std::wstring> that I need to use within my  
> lambda. 
>  
> This all being the case, the following is the original BOOST_FOREACH: 
>  
> BOOST_FOREACH(boost::property_tree::ptree::value_type &v, IniTree) 
>  
>                                   
> IniSections.push_back(ConvertToWString(v.first)); 
>  
> And the following is the converted lambda: 
>  
> std::for_each(IniTree.begin(), IniTree.end(), [&]  
> (boost::property_tree::ptree::value_type &v) 
>  
>         { 
>  
>                             IniSections.push_back(ConvertToWString(v.first)); 
>  
>         }); 
>  
> Is this the right way to go about the conversion—have I missed anything? 

That looks correct to me. Note that there is also a boost::for_each
function in Boost.Range that allows you to avoid repeating the range
expression:

boost::for_each(IniTree, [&](boost::property_tree::ptree::value_type &v)
{
    IniSections.push_back(ConvertToWString(v.first)); 
}); 

Doesn't make much of a difference in this case, but it can be useful
when the range expression is longer.

Regards,
Nate