A type Func satisfies JoinNodeFunctionObject if it meets the following requirements:

JoinNodeFunctionObject Requirements: Pseudo-Signature, Semantics

Func::Func(const Func&)

Copy constructor.



Key Func::operator()(const Input &v)

Requirements: The Key and Input types must be the same as the K and the corresponding element of the OutputTuple template arguments of the join_node instance to which the Func object is passed during construction.

Returns key to be used for hashing input messages.