import TestLib; StartTest("erase"); string s = "abcdef"; assert(erase(s,2,2) == "abef"); assert(erase(s,-1,2) == "abcdef"); assert(erase(s,7,1) == "abcdef"); assert(erase(s,3,0) == "abcdef"); assert(erase(s,5,2) == "abcde"); EndTest();