Contents
V302. Member operator[] of 'foo' class has a 32-bit type argument. Use memsize-type here.
This rule belongs to the "Diagnosis of 64-bit errors" group. The rules in this group are no longer developed and may be disabled in the future. If you use these rules, please contact our support team—we will help you find a replacement or suggest an alternative solution.
The analyzer detected a potential error of working with classes that contain operator[]. Classes with an overloaded operator[] are usually a kind of an array where the index of the item being called is operator[] argument. If operator[] has a 32-bit type argument it might indicate an error.
Let us consider an example leading to the warning V302:
class MyArray {
std::vector<float> m_arr;
...
float &operator[](int i) //V302
{
DoSomething();
return m_arr[i];
}
} A;
...
int x = 2000;
int y = 2000;
int z = 2000;
A[x * y * z] = 33;If the class is designed to work with many arguments, implementing operator[] like this is incorrect because it does not allow addressing the items whose numbers are more than UINT_MAX. To diagnose the error in the example above you should point to the potentially incorrect operator[]. The expression "x * y * z" does not look suspicious because there is no implicit type conversion. When we correct operator[] in the following way:
float &operator[](ptrdiff_t i);PVS-Studio analyzer warns about a potential error in the line "A[x * y * z] = 33;" and now we can make the code absolutely correct. Here is an example of the corrected code:
class MyArray {
std::vector<float> m_arr;
...
float &operator[](ptrdiff_t i) //V302
{
DoSomething();
return m_arr[i];
}
} A;
...
ptrdiff_t x = 2000;
ptrdiff_t y = 2000;
ptrdiff_t z = 2000;
A[x * y * z] = 33;The related diagnostic warnings are V108 and V120.
Was this page helpful?
