.\"
.\" Copyright (c) 2025 Robert Clausecker <fuz@FreeBSD.org>
.\"
.\" SPDX-License-Identifier: BSD-2-Clause
.\"
.Dd November 10, 2025
.Dt MEMALIGNMENT 3
.Os
.Sh NAME
.Nm memalignment
.Nd find the memory alignment of an object
.Sh SYNOPSIS
.Lb libc
.In stdlib.h
.Ft size_t
.Fn memalignment "const void *ptr"
.Sh DESCRIPTION
The
.Fn memalignment
function determines the alignment of the object pointed to by
.Fa ptr .
This alignment is a power of\~2, and may be larger than the range
supported by the
.Sy alignof
operator.
The value returned can be compared to the result of
.Sy alignof ,
and if it is greater or equal, the alignment requirement of the operand
is satisfied.
.Sh RETURN VALUES
Returns the alignment of
.Fa ptr
as a power of\~2.
If
.Fa ptr
is a null pointer, an alignment of zero is returned.
An alignment of zero indicates that the tested pointer cannot be used to
access an object of any type.
.Sh SEE ALSO
.Xr aligned_alloc 3 ,
.Xr posix_memalign 3
.Sh STANDARDS
The
.Fn memalignment
function conforms to
.St -isoC-2023 .
.Sh HISTORY
The
.Fn memalignment
function was added in
.Fx 15.1.
.Sh AUTHOR
.An Robert Clausecker Aq Mt fuz@FreeBSD.org