Normal "let":

In a function (which does not use "do"), you can use "let" to make local variables. The word "in" separates the local variable declaration from the part of your function where you want to use that variable. Loosely translating from Haskell to C++:

Haskell:

> let foo = bar in baz

C++:

> /* insert correct type here */ foo = bar;

> baz