C++ segmentation error when first parameter is null in comparison operator overload
- by user1774515
I am writing a class called Word, that handles a c string and overloads the <, , <=, = operators.
word.h:
friend bool operator<(const Word &a, const Word &b);
word.cc:
bool operator<(const Word &a, const Word &b) {
if(a == NULL && b == NULL)
return false;
if(a == NULL)
return true;
if(b == NULL)
return false;
return a.wd < b.wd; //wd is a valid c string
}
main:
char* temp = NULL; //EDIT: i was mistaken, temp is a char pointer
Word a("blah"); //a.wd = [b,l,a,h]
cout << (temp<a);
i get a segmentation error before the first line of the operator< method after the last line in the main. I can correct the problem by writing
cout << (a>temp);
where the operator> is similarly defined and i get no errors. but my assignment requires (temp < a) to work so this is where i ask for help.
EDIT: i made a mistake the first time and i said temp was of type Word, but it is actually of type char*. so i assume that the compiler converts temp to a Word using one of my constructors. i dont know which one it would use and why this would work since the first parameter is not Word.
here is the constructor i think is being used to make the Word using temp:
Word::Word(char* c, char* delimeters=NULL) {
char *temporary = "\0";
if(c == NULL)
c = temporary;
check(stoppers!=NULL, "(Word(char*,char*))NULL pointer"); //exits the program if the expression is false
if(strlen(c) == 0)
size = DEFAULT_SIZE; //10
else
size = strlen(c) + 1 + DEFAULT_SIZE;
wd = new char[size];
check(wd!=NULL, "Word(char*,char*))heap overflow");
delimiters = new char[strlen(stoppers) + 1]; //EDIT: changed to []
check(delimiters!=NULL,"Word(char*,char*))heap overflow");
strcpy(wd,c);
strcpy(delimiters,stoppers);
count = strlen(wd);
}
wd is of type char*
thanks for looking at this big question and trying to help. let me know if you need more code to look at
