I use this construct frequently in my C++11 projects. It can serve to make the code more readable. Here's an example of a line of code I wrote recently. It makes use of Boost.Range in addition to C++11 lambdas:
vector<message> messages; push_back(messages, message_ids | transformed(lookup_message_by_id) | filtered(newer_than_one_year) | filtered(not_hidden) | filtered(satisfies_user_preference));
I also often use this kind of constructs: it is for me more readable (in this example) than inline lambdas, and more importantly, named lambdas are necessary when I have to reuse them in the same enclosing function, for example: push_back(hidden_messages, ... | filtered(newer_than_one_year) | filtered(hidden) | filtered(satisfies_user_preference)); Without c++11 lambdas, I would be very happy to use Boost.Local (whether it is accepted in Boost or not, I have no opinion on this issue), because these named lambdas: - don't need to be tested separately (one-or-two liners) - only belong to the logic of the enclosing function (I would prefer using copy/paste to reuse a (small) block of code rather than polluting the outer scope) - can bind to local variables, and can be very easily replaced by c++11 lambdas when they become available to me. Rafaël