Hello,
In the following union, the size of the union variable displayed using sizeof operator is 52. If I comment the integer, the size is 50. If I include double variable also, the size is 56. What is the reason for this? The size should only be 50 right (size of Largest member)
Code:union myUnion { int var1; char char1; //double mydouble1; char string1[50]; };
My guess is alignment issues might be causing greater size; possibly because of a compiler bug or by design.
Tim S.
"...a computer is a stupid machine with the ability to do incredibly smart things, while computer programmers are smart people with the ability to do incredibly stupid things. They are,in short, a perfect match.." Bill Bryson
It's adding padding so that if you had an array of these unions, then each foo[i].var1 would be aligned to a 4 byte boundary (the size of an int here).
Or with a double, the padding ensures that each foo[i].mydouble1 would be aligned to a 8 byte boundary (the size of a double).
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