Most functional programming languages (e.g. Common Lisp, Scheme / Racket, Clojure, Haskell, Scala, Ocaml, SML) support some common higher-order functions on lists, such as map, filter, takeWhile, dropWhile, foldl, foldr (see e.g. Common Lisp, Scheme / Racket, Clojure side-by-side reference sheet, the Haskell, Scala, OCaml, and the SML documentation.)
Does C++11 have equivalent standard methods or functions on lists? For example, consider the following Haskell snippet:
let xs = [1, 2, 3, 4, 5]
let ys = map (x -> x * x) xs
How can I express the second expression in modern standard C++?
std::list<int> xs = ... // Initialize the list in some way.
std::list<int> ys = ??? // How to translate the Haskell expression?
What about the other higher-order functions mentioned above?
Can they be directly expressed in C++?
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Even more, C++ have such functions, take a look to algorithm (or with C++11 additions) header:
std::transform
std::for_each
std::remove_copy_if
They can be easily used with any container.
For example your code can be expressed like this (with C++11 lambdas for easy coding):
std::vector<int> x = {1, 2, 3, 4, 5};
std::vector<int> y;
std::transform(x.begin(), x.end(), std::back_inserter(y), [](int elem){ return elem * elem; });
Less intuitive, but you can easily wrap the std::transform call into function which would return new container (with move semantics for better perfomance).
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