Enum AsInitialized 

pub enum AsInitialized {}

The byte ranges initialized in T are also initialized in the referent of a Ptr<T>.

Formally: uninitialized bytes may only be present in Ptr<T>’s referent where they are guaranteed to be present in T. This is a dynamic property: if, at a particular byte offset, a valid enum discriminant is set, the subsequent bytes may only have uninitialized bytes as specified by the corresponding enum.

Formally, given len = size_of_val_raw(ptr), at every byte offset, b, in the range [0, len):

• If, in any instance t: T of length len, the byte at offset b in t is initialized, then the byte at offset b within *ptr must be initialized.

• Let c be the contents of the byte range [0, b) in *ptr. Let S be the subset of valid instances of T of length len which contain c in the offset range [0, b). If, in any instance of t: T in S, the byte at offset b in t is initialized, then the byte at offset b in *ptr must be initialized.

  Pragmatically, this means that if *ptr is guaranteed to contain an enum type at a particular offset, and the enum discriminant stored in *ptr corresponds to a valid variant of that enum type, then it is guaranteed that the appropriate bytes of *ptr are initialized as defined by that variant’s bit validity (although note that the variant may contain another enum type, in which case the same rules apply depending on the state of its discriminant, and so on recursively).

Trait Implementations

impl Validity for AsInitialized