Linux.com

The use of “lambda” originates from functional programming and lambda calculus, where a lambda abstraction defines an unnamed function. Lambda functions or Lambdas in C++ are one of the more interesting things to look forward to in the next C++ standard; giving us the ability to treat functions as first class objects at last; composing them inline and treating them as class objects. Up until now we've scraped by with pointers to functions, and various libraries like Boost Lambda, both of which approaches suck.