functions in c++

[Neeru]

Somewhere I came across a code like this

  class_name::function( [=]
       {
         function1();
         function2();
         function3();
       });

This was passed to some other template class. I think that this entire list of function calls which are enclosed within { and } as function body of function. But what is [=] mean ?
what is the good book which explains all these stuff?

[JLBorges]

Overview: http://en.wikipedia.org/wiki/Anonymous_function#C.2B.2B

Book: http://en.wikipedia.org/wiki/Anonymous_function#C.2B.2B

[Neeru]

Thanks for your reply.

[JLBorges]

EDIT:
Book: http://www.amazon.com/Primer-5th-Edition-Stanley-Lippman/dp/0321714113