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Nonportable Behavior	Definition	Annex J Section
unspecified Unspecified behavior	Behavior for which the standard provides two or more possibilities and imposes no further requirements on which is chosen in any instance.	J.1
undefined Undefined behavior	Behavior, upon use of a nonportable or erroneous program construct or of erroneous data, for which the standard imposes no requirements. An example of undefined behavior is the behavior on integer overflow.	J.2
implementationImplementation-defined behavior	Unspecified behavior whereby each implementation documents how the choice is made.	J.3
localeLocale-specific behavior	Behavior that depends on local conventions of nationality, culture, and language that each implementation documents.	J.4

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This noncompliant code example uses the complement operator in the test for unsigned integer overflow.:

Code Block

bgColor	#FFCCCC
lang	c

unsigned int ui1, ui2, sum;

if (~ui1 < ui2) {
  /* Handle error condition */
}
sum = ui1 + ui2;

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This compliant solution implements a strictly conforming test for unsigned overflow.:

Code Block

bgColor	#ccccff
lang	c

unsigned int ui1, ui2, sum;

if (UINT_MAX - ui1 < ui2) {
  /* Handle error condition */
}
sum = ui1 + ui2;

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