Our website uses cookies to enhance your browsing experience.
Accept
to the top
close form

Fill out the form in 2 simple steps below:

Your contact information:

Step 1
Congratulations! This is your promo code!

Desired license type:

Step 2
Team license
Enterprise license
** By clicking this button you agree to our Privacy Policy statement
close form
Request our prices
New License
License Renewal
--Select currency--
USD
EUR
* By clicking this button you agree to our Privacy Policy statement

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

close form
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

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

close form
check circle
Message submitted.

Your message has been sent. We will email you at


If you do not see the email in your inbox, please check if it is filtered to one of the following folders:

  • Promotion
  • Updates
  • Spam

Webinar: Parsing C++ - 10.10

>
>
>
V702. Classes should always be derived …
menu mobile close menu
Analyzer diagnostics
General Analysis (C++)
General Analysis (C#)
General Analysis (Java)
Micro-Optimizations (C++)
Diagnosis of 64-bit errors (Viva64, C++)
Customer specific requests (C++)
MISRA errors
AUTOSAR errors
OWASP errors (C#)
Problems related to code analyzer
Additional information
toggle menu Contents

V702. Classes should always be derived from std::exception (and alike) as 'public'.

Sep 08 2014

The analyzer has detected a class derived from the std::exception class (or other similar classes) through the private or protected modifier. What is dangerous about such inheritance is that in case of nonpublic inheritance, the attempt to catch a std::exception will fail.

The error is often a result of the programmer forgetting to specify an inheritance type. According to the language rules, the default inheritance type is private inheritance. It results in exception handlers behaving other way than expected.

For example, see the following incorrect code:

class my_exception_t : std::exception // <=
{
public:
  explicit my_exception_t() { }
  virtual const int getErrorCode() const throw() { return 42; }
};
....
try
  { throw my_exception_t(); }
catch (const std::exception & error)
  { /* Can't get there */ }
catch (...)
  { /* This code executed instead */ }

The code to catch all the standard and user exceptions "catch (const std::exception & error)" won't work properly because private inheritance does not allow for implicit type conversion.

To make the code run correctly, we need to add the public modifier before the base class std::exception in the list of base classes:

class my_exception_t : public std::exception
{
  ....
}

This diagnostic is classified as:

You can look at examples of errors detected by the V702 diagnostic.