Question

bool operator == (const MyString& left, const MyString& right)
{
    if(left.value == right.value)
        return true;
    else return false;
}
bool operator != (const MyString& left, const MyString& right)
{
    if(left == right)
        return false;
    else 
        return true;
}
bool operator < (const MyString& left, const MyString& right)
{
    if(strcmp(left.value, right.value) == -1)
        return true;
    else
        return false;
}
bool operator > (const MyString& left, const MyString& right)
{
    if(strcmp(left.value, right.value) == 1)
        return true;
    else
        return false;
}
bool operator <= (const MyString& left, const MyString& right)
{
    if(strcmp(left.value, right.value) == -1 || strcmp(left.value, right.value) == 0)
        return true;
    else
        return false;
}
bool operator >= (const MyString& left, const MyString& right)
{
    if(strcmp(left.value, right.value) == 1 || strcmp(left.value, right.value) == 0)
        return true;
    else
        return false;
}

These are my implemented comparison operators for my MyString class, but they fail the test program that my professor gave me and could use some direction. What is the problem?

Answer 1

You can express each comparator with just two of them:

bool operator == (const MyString& left, const MyString& right) {
    return strcmp(left.value, right.value) == 0;
}
bool operator < (const MyString& left, const MyString& right) {
    return strcmp(left.value, right.value) < 0;
}

bool operator != (const MyString& left, const MyString& right) {
    return !(left == right);
}
bool operator > (const MyString& left, const MyString& right) {
    return !(left == right) && !(left < right);
}
bool operator <= (const MyString& left, const MyString& right) {
    return left < right || left == right;
}
bool operator >= (const MyString& left, const MyString& right) {
    return !(left < right);
}