std::is_a_digit

checks wheter its argument is a digit

Parameter

This function must be called on character-values only.

if is_a_digit('3'): println! "3 is a digit" : println! "3 is not a digit"

3 is a digit

if is_a_digit('a'): println! "a is a digit" : println! "a is not a digit"

a is not a digit

std_types::character	a unicode code point encoded as a 32-bit value
std::is_a_letter	checks wheter its argument is a letter (upper or lower case)
std::is_a_letter_character	returns for letter characters