V3521. AUTOSAR. The loop counter should not have floating-point type.

This diagnostic rule is based on the software development guidelines developed by AUTOSAR (AUTomotive Open System ARchitecture).

Since floating-point numbers cannot accurately represent all real numbers, the number of iterations may vary for loops relying on such variables.

Consider the following example:

void foo(void) {
  for (float A = 0.1f; A <= 10.0f; A += 0.1f) {
    ....
  }
}

This loop may iterate 99 or 100 times. The accuracy of operations involving real numbers depends on the compiler, optimization mode, and many other things.

It is better to rewrite the loop as follows:

void foo(void) {
  for (int count = 1; count <= 100; ++count) {
    float A = count / 10.0f;
  }
}

Now it is guaranteed to iterate exactly 100 times, while the 'A' variable can be used for the calculations.

This diagnostic is classified as: