Module core::mem

Basic functions for dealing with memory.

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

Structs

Discriminant

Opaque type representing the discriminant of an enum.

ManuallyDrop

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

Functions

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.

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 &U, 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.

Unions

MaybeUninit

A wrapper type to construct uninitialized instances of T.