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This CUBE() macro definition is non-compliant because it fails to parethesize parenthesize the macro expansion.
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#define CUBE(X) (X) * (X) * (X) int i = 3; int a = 81 / CUBE(i); |
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However, if a parameter appears several times in the expansion, the macro may not work properly if the actual argument is an expression with side effects. Given the CUBE() macro above, the invocation:
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int a = 81 / CUBE(i++); |
expands to:
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int a = 81 / (i++ * i++ * i++);
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which is undefined (see \[[EXP30|EXP30-C. Do not depend on order of evaluation between sequence points]\]). |
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