If in doubt about operator precedence, parenthesize

Reason

Avoid errors. Readability. Not everyone has the operator table memorized.

Example

const unsigned int flag = 2;
unsigned int a = flag;

if (a & flag != 0)  // bad: means a&(flag != 0)

Note: We recommend that programmers know their precedence table for the arithmetic operations, the logical operations, but consider mixing bitwise logical operations with other operators in need of parentheses.

if ((a & flag) != 0)  // OK: works as intended

Note

You should know enough not to need parentheses for:

if (a < 0 || a <= max) {
    // ...
}

Enforcement

• Flag combinations of bitwise-logical operators and other operators.
• Flag assignment operators not as the leftmost operator.
• ???