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This definition means that, when allocating storage space, only the first member, num, is considered. Consequently, the result of accessing the member data of a variable of type struct flexArrayStruct is undefined. DCL38-C. Use the correct syntax when declaring flexible array members describes the correct way to declare a struct with a flexible array member.
To avoid the potential for undefined behavior, structures that contain a flexible array member should always be accessed with a pointer as shown in the following code example.
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