10.3.2. Lambda Expressions
The predicates we pass to an algorithm must have exactly one or two parameters, depending on whether the algorithm takes a unary or binary predicate, respectively. However, sometimes we want to do processing that requires more arguments than the algorithm’s predicate allows. For example, the solution you wrote for the last exercise in the previous section had to hard-wire the size 5 into the predicate used to partition the sequence. It would be move useful to be able to partition a sequence without having to write a separate predicate for every possible size.