__ALIGNOF__(3) | Library Functions Manual | __ALIGNOF__(3) |
__alignof__
—
__alignof__
(void
x);
__alignof__
() operator returns the alignment of its
operand. The operand can be a type or an expression. If the operand is a
‘lvalue’, the return value represents the required alignment of
the underlying type, not the actual alignment of the specified
‘lvalue’.
The returned value is specific to the architecture and the ABI. If
the architecture does not impose strict alignment requirements,
__alignof__
() returns the minimum required
alignment. If __aligned(3)
is used to increase the alignment, __alignof__
()
returns the specified alignment.
sizeof
() operator. If
the architecture aligns integers along 32-bit address boundaries, the
following should print the value 4.
(void)printf("%d\n", __alignof__(int));
On the other hand, the following example should print the value 1, even though this is unlikely to be the actual alignment of the structure member.
struct align { int x; char y; } a; (void)printf("%d\n", __alignof__(a.y));
December 20, 2010 | NetBSD 9.0 |