The analyzer has detected a potential error. The '!=' or '== !' operator should be probably used instead of the '=!' operator. Such errors most often occur through misprints.
Consider an example of incorrect code:
bool a, b; ... if (a =! b) { ... }
It's most probably that this code should check that the 'a' variable is not equal to 'b'. If so, the correct code should look like follows:
if (a != b) { ... }
The analyzer accounts for formatting in the expression. That's why if it is exactly assignment you need to perform - not comparison - you should specify it through parentheses or blanks. The following code samples are considered correct:
if (a = !b) ... if (a=(!b)) ...
This diagnostic is classified as: