To get a trial key
fill out the form below
Team License (a basic version)
Enterprise License (extended version)
* By clicking this button you agree to our Privacy Policy statement

Request our prices
New License
License Renewal
--Select currency--
USD
EUR
GBP
RUB
* By clicking this button you agree to our Privacy Policy statement

Free PVS-Studio license for Microsoft MVP specialists
* By clicking this button you agree to our Privacy Policy statement

To get the licence for your open-source project, please fill out this form
* By clicking this button you agree to our Privacy Policy statement

I am interested to try it on the platforms:
* By clicking this button you agree to our Privacy Policy statement

Message submitted.

Your message has been sent. We will email you at


If you haven't received our response, please do the following:
check your Spam/Junk folder and click the "Not Spam" button for our message.
This way, you won't miss messages from our team in the future.

>
>
>
V302. Member operator[] of 'foo' class …
Analyzer diagnostics
Additional information
Contents

V302. Member operator[] of 'foo' class has a 32-bit type argument. Use memsize-type here.

Jun 13 2012

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.

This website uses cookies and other technology to provide you a more personalized experience. By continuing the view of our web-pages you accept the terms of using these files. If you don't want your personal data to be processed, please, leave this site.
Learn More →
Accept