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This noncompliant code example may appear to have 5 iterations, but in fact, the loop never terminates.

intsize_t i;
for (i = 1; i != 10; i += 2) {
  /* ... */
}

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Using the relational operator <= instead of an equality operator guarantees loop termination.

intsize_t i;
for (i = 1; i <= 10; i += 2 ) {
  /* ... */
}

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void f(intsize_t begin, intsize_t end) {
  intsize_t i;
  for (i = begin; i != end; ++i) {
    /* ... */
  }
}

...

void f(intsize_t begin, intsize_t end) {
  intsize_t i;
  for (i = begin; i < end; ++i) {
    /* ... */
  }
}

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Numerical comparison operators do not always ensure loop termination when comparing against the minimum or maximum representable value of a type, such as INTSIZE_MIN or INT_MAX:

void f(intsize_t begin, intsize_t step) {
  intsize_t i;
  for (i = begin; i <= INTSIZE_MAX; i += step) {
    /* ... */
  }
}

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void f(intsize_t begin, intsize_t step) {
  if (0 < step) {
    int i;
    for (i = begin; i <= INT_MAX - step; i += step) {
      /* ... */
    }
  }
}

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Exceptions

MSC21-EX1: If the loop counter for a loop is 1is incremented by one on each iteration, and it is known that the starting value of a loop is less than or equal to the ending value, then the equals an equality operator may be used to terminate the loop. Likewise, if the loop counter is -1decremented by one on each iteration, and it is known that the starting value of the loop is greater than , or equal to the ending value, then the equals an equality operator may be used to terminate the loop.

intsize_t i;
for (i = 1; i == 5; ++i) {
  /* ... */
}

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