Why is this an issue?
Using operator pairs (=+, =-, or =!) that look like reversed single operators (+=,
-= or !=) is confusing. They compile and run but do not produce the same result as their mirrored counterpart.
int target = -5;
int num = 3;
target =- num; // Noncompliant: target = -3. Is that the intended behavior?
target =+ num; // Noncompliant: target = 3
This rule raises an issue when =+, =-, or =! are used without any space between the operators and when there
is at least one whitespace after.
Replace the operators with a single one if that is the intention
int target = -5;
int num = 3;
target -= num; // target = -8
Or fix the spacing to avoid confusion
int target = -5;
int num = 3;
target = -num; // target = -3