To get a trial key
fill out the form below
Team license
Enterprise license
** By clicking this button you agree to our Privacy Policy statement

Request our prices
New License
License Renewal
--Select currency--
* 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.

V806. Decreased performance. The expres…
Analyzer diagnostics
General Analysis (C++)
General Analysis (C#)
General Analysis (Java)
Diagnosis of 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

V806. Decreased performance. The expression of strlen(MyStr.c_str()) kind can be rewritten as MyStr.length().

Aug 16 2011

Analyzer found a construct which potentially can be optimized. The length of a string located in the container is calculated by using the strlen() function or by function similar to it. This operation is excessive, as the container possesses a special function for string length calculation.

Let's review this example:

static UINT GetSize(const std::string& rStr)
  return (strlen(rStr.c_str()) + 1 );

This code belongs to a real-life application. Usually such funny code fragments are created during careless refactoring. This code is slow and, even more, quite possibly even unnecessary. When it is required you can just write "string::length() + 1".

Nevertheless, if you are willing to create a special function for calculating the size of a null-terminated string, it should appear as follows:

inline size_t GetSize(const std::string& rStr)
  return rStr.length() + 1;


One should remember that "strlen(MyString.c_str())" and "MyString.length()" operations will not always generate the same result. The differences will appear in case a string contains null characters besides the terminal one. However such situations can be viewed as a very bad design practice, so the V806 warning message is a great reason to consider the possibility of refactoring. Even if the developer who created this code understands its' operational principles quite well, nevertheless it will be hard to understand this code for his colleagues. They will wonder about the purpose of such a style and could potentially replace the call to "strlen()" function with "length()", thus creating a bug in the program. So one should not be lazy and should replace it with such a code in which operational principles are clear and intelligible to even an outsider developer. For instance, if the string contains null characters, than there is a high probability that it is not a string at all but an array of bytes. An in such a case the std::vector or your own custom classes should be used instead.

Unicorn with delicious cookie
Our website uses cookies to enhance your browsing experience.