D语言限制字符

import std.stdio;
import std.string;

void main() { 
   string s = "H123Hello1";  

   string result = munch(s, "0123456789H"); 
   writeln("Restrict trailing characters:",result);  

   result = squeeze(s, "0123456789H"); 
   writeln("Restrict leading characters:",result); 

   s = "  Hello World  "; 
   writeln("Stripping leading and trailing whitespace:",strip(s)); 
}