# V3060\. A value of variable is not modified\. Consider inspecting the expression\. It is possible that other value should be present instead of '0'\.

The analyzer detected a suspicious bitwise expression\. This expression was meant to change certain bits in a variable, but the value this variable refers to will actually stay unchanged\.

Consider the following example:

```cpp
A &= ~(0 << Y);
A = A & ~(0 << Y);
```

The programmer wanted to clear a certain bit in the variable's value but made a mistake and wrote 0 instead of 1\.

Both expressions evaluate to the same result, so let's examine the second line as a clearer example\. Suppose we have the following values of the variables in bit representation:

A \= 0\.\.0101

A \= 0\.\.0101 & \~\(0\.\.0000 << 0\.\.00001\) 

Shifting the value 0 by one bit to the left won't change anything; we'll get the following expression:

A \= 0\.\.0101 & \~0\.\.0000 

Then, the bitwise negation operation will be executed, resulting in the following expression:

A \= 0\.\.0101 & 11111111 

After executing the bitwise "AND" operation, the original and resulting expressions will turn out to be the same:

A \= 0\.\.0101 

The fixed version of the code should look like this:

```cpp
A &= ~(1 << Y);
A = A & ~(1 << Y);
```