Returns the array index at which the (n+1)th code point begins.
The input to this function MUST be validly encoded. This is enforced by the function's in-contract.
the string to be counted
the current code point index
See Implementation
Returns the array index at which the (n+1)th code point begins.
The input to this function MUST be validly encoded. This is enforced by the function's in-contract.