The Amplification specifies that the value be "positive". However, that can be interpreted as "greater than" zero. However, according the to C standard (C99 7.21.1/2) it is well defined to call these functions with a value of 0:
1) Given that 0 has well-defined meaning, does 'positive' imply "greater than zero" or "greater than or equal to zero"?Where an argument declared as size_t n specifies the length of the array for a function, n can have the value zero on a call to that function. Unless explicitly stated otherwise in the description of a particular function in this subclause, pointer arguments on such a call shall still have valid values, as described in 7.1.4. On such a call, a function that locates a character finds no occurrence, a function that compares two character sequences returns zero, and a function that copies characters copies zero characters.
2) If positive refers to "greater than zero", is there an example or rationale for excluding this well-defined behavior?