Requirements on types

For the first version:

• InputIterator1 is a model of Input Iterator.

• InputIterator2 is a model of Input Iterator.

• T is a model of Assignable.

• If x is an object of type T, y is an object of InputIterator1's value type, and z is an object of InputIterator2's value type, then x + y * z is defined.

• The type of x + y * z is convertible to T.

For the second version:

• InputIterator1 is a model of Input Iterator.

• InputIterator2 is a model of Input Iterator.

• T is a model of Assignable.

• BinaryFunction1 is a model of Binary Function.

• BinaryFunction2 is a model of Binary Function.

• InputIterator1's value type is convertible to BinaryFunction2's first argument type.

• InputIterator2's value type is convertible to BinaryFunction2's second argument type.

• T is convertible to BinaryFunction1's first argument type.

• BinaryFunction2's return type is convertible to BinaryFunction1's second argument type.

• BinaryFunction1's return type is convertible to T.