CODEWITHSUNDEEP
cmemory
Horia Pantelimon
Horia Pantelimon

Reputation: 43

about Struct Memory Managemet in C

typedef struct{
 int a:1, b:1;
}test;

a and b are capable to store a number up to 255. If somehow variable a stores a bigger value than that, this will affect the value of b,right? I am terrible at memory management. Also, is it recommended to alter the size of a field in a struct this way?

Upvotes: 1

Views: 68

Answers (1)

user2736738
user2736738

Reputation: 30936

Most variables in C have a size that is an integral number of bytes. Bit-fields are a part of a structure that don't necessarily occupy a integral number of bytes; they can any number of bits. Multiple bit-fields can be packed into a single storage unit. Here these are 1 bit bitfiels capable of holding 0 and -1.

And in case there is a larger number being stored in a 1 bit bitfield then this would be undefined behavior (signed overflow).

More prominently use unsigned type in bit field in this case

typedef struct{
 unsigned int a:1, b:1;
}test;

Upvotes: 1

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