passing 'xxx' as 'this' argument discards qualifiers
一段代码:boolBigNum::operator==(constint&n){...}BigNumBigNum::operator/(constBigNum&n){if(n==0){...}...}报错:error:nomatchfor‘operator==’(operandtypesare‘constBigNum’and‘int’)if(n==0){^bigNum.cpp:102:6:note