-----Description-----  
This task involves determining whether every character in a provided string is a digit. The objective is to check if all characters fall within the standard digit range, returning true if they do and false otherwise.

-----Input-----  
The input consists of:  
• s: A string whose characters will be analyzed to determine if they are all digits.

-----Output-----  
The output is a boolean value:  
• true if every character in the string is a digit;  
• false if at least one character is not a digit (note that the empty string returns true).

-----Note-----  
It is assumed that the input is a well-formed string. The function uses an iterator to examine every character.