Re: [Boost-users] boost::lambda question

From: Sebastian Redl (sebastian.redl_at_[hidden])
Date: 2006-03-11 11:41:40

Robert Caldecott wrote:

>OK, I'm a bit of a boost noob.  I have a container of std::wstring's
>and I want to use a lambda expression in a for_each loop to pass each
>string to a WinAPI function - however, I need access to the c_str()
>method, and this is giving me a problem.
>
>For example, if I want to use the DeleteFile WinAPI call, I want to
>write something like:
>
>std::vector<std::wstring> v;
>...
>for_each(v.begin(), v.end(), ::DeleteFile(_1));
>
>But the above won't work as I need to pass the 'C' string to ::DeleteFile.
>
>So, I really want to be able to do something like this:
>
>for_each(v.begin(), v.end(), ::DeleteFile(_1.c_str()));
>
>Any ideas how I can access a member function (like c_str()) using a
>lambda placeholder?
>  
>
You need to use the binders of lambda, like this:

for_each(v.begin(), v.end(), ::DeleteFile(bind(&std::wstring::c_str, _1)));

Sebastian Redl