Module mem

Basic functions for dealing with memory.

This module contains functions for querying the size and alignment of types, initializing and manipulating memory.

Macros

offset_of

Expands to the offset in bytes of a field from the beginning of the given type.

Structs

Discriminant

Opaque type representing the discriminant of an enum.

ManuallyDrop

A wrapper to inhibit the compiler from automatically calling T’s destructor. This wrapper is 0-cost.

AssumeExperimental

Configurable proof assumptions of TransmuteFrom.

Traits

TransmuteFromExperimental

Marks that Src is transmutable into Self.

Functions

align_of

Returns the ABI-required minimum alignment of a type in bytes.

align_of_val

Returns the ABI-required minimum alignment of the type of the value that val points to in bytes.

discriminant

Returns a value uniquely identifying the enum variant in v.

drop

Disposes of a value.

forget

Takes ownership and “forgets” about the value without running its destructor.

min_align_ofDeprecated

Returns the ABI-required minimum alignment of a type in bytes.

min_align_of_valDeprecated

Returns the ABI-required minimum alignment of the type of the value that val points to in bytes.

needs_drop

Returns true if dropping values of type T matters.

replace

Moves src into the referenced dest, returning the previous dest value.

size_of

Returns the size of a type in bytes.

size_of_val

Returns the size of the pointed-to value in bytes.

swap

Swaps the values at two mutable locations, without deinitializing either one.

take

Replaces dest with the default value of T, returning the previous dest value.

transmute^⚠

Reinterprets the bits of a value of one type as another type.

transmute_copy^⚠

Interprets src as having type &Dst, and then reads src without moving the contained value.

uninitialized^⚠Deprecated

Bypasses Rust’s normal memory-initialization checks by pretending to produce a value of type T, while doing nothing at all.

zeroed^⚠

Returns the value of type T represented by the all-zero byte-pattern.

align_of_val_raw^⚠Experimental

Returns the ABI-required minimum alignment of the type of the value that val points to in bytes.

copyExperimental

Bitwise-copies a value.

forget_unsizedExperimental

Like forget, but also accepts unsized values.

size_of_val_raw^⚠Experimental

Returns the size of the pointed-to value in bytes.

variant_countExperimental

Returns the number of variants in the enum type T.

Unions

MaybeUninit

A wrapper type to construct uninitialized instances of T.