Can “signed char” and “unsigned char” always be transferred to each other without data loss?

Question

In C ++, we can have signed charand unsigned char, which are the same size, but contain different ranges of values.

In the following code:

signed char signedChar = -10;
unsigned char unsignedChar = static_cast<unsigned char>( signedChar );
signedChar = static_cast<signed char>( unsignedChar );

will signed charretain its value regardless of its original value?

Answer 1

No, there is no such guarantee. Converting from signed charto unsigned charis correct, since all conversions are integers without subscribers in C ++ (and C). However, the result of this conversion can easily fall outside the bounds of the original signed type (it will happen in your example c -10).

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Answer 3

AFAIK, this actor will never change the byte, just change his mind.

Answer 4

My first guess would be "maybe." Have you tried testing this with various inputs?