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Arithmetic overflow: Left shift of a negative signed number is undefined behavior (io.4)
Remarks
This warning indicates the code left shifts a negative signed integral value, which is nonportable and triggers implementation defined behavior.
Code analysis name: LEFTSHIFT_NEGATIVE_SIGNED_NUMBER
Example
void leftshift(int shiftCount) { const auto result = -1 << shiftCount; // C26453 reported here // code } To correct this warning, use the following code:
void leftshift(int shiftCount) { const auto result = ~0u << shiftCount; // OK // code } See also
C26450
C26451
C26452
C26454
ES.101: Use unsigned types for bit manipulation
ES.102: Use signed types for arithmetic