string is wideinteger indicates whether a value is an integer that can fit into storage allocated for a wide integer.
string is wideinteger trims the whitespace from value and returns true if it is an integer that fits into storage allocated for a wide integer, or false otherwise. If value does not fit into storage allocated for a wide integer, and -failindex is provided, -1 is stored in the variable naed varname.
In the case of under or overflow in the value, 0 is returned and varname, if provided as an argument to -failindex, will have a value of -1.
[Is there a wiki page that discusses the valid forms for a wide integer? If so, please replace this comment with the page reference. Thank you.]