Assume this struct:
typedef struct test {
unsigned int a : 3;
unsigned int b : 3;
} test;
doing a sizeof(test) outputs 4. The above data can be saved in 6 bits (or only 1 byte) so why is gcc still reserving the size of int?
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1Any question involving bitfields usually involves an answer that ends with "don't use bitfields." – tadman May 14 '20 at 21:13
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3Or use `unsigned char` instead of `unsigned int` – Barmar May 14 '20 at 21:14
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1Does this answer your question? [Size of structure with bit fields](https://stackoverflow.com/questions/24725188/size-of-structure-with-bit-fields) – Hitokiri May 14 '20 at 21:16
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another link can help you https://stackoverflow.com/questions/4129961/how-is-the-size-of-a-struct-with-bit-fields-determined-measured – Hitokiri May 14 '20 at 21:18
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1Re "*why is gcc still reserving the size of int?*", Because you asked to reserve bits in an `unsigned int`. – ikegami May 14 '20 at 21:38
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How is 1 or 4 bytes a concern for your code? – chux - Reinstate Monica May 14 '20 at 22:42