<s>
assert.h	B-Language
is	O
a	O
header	B-Language
file	I-Language
in	O
the	B-Language
C	I-Language
standard	I-Language
library	I-Language
.	O
</s>
<s>
It	O
defines	O
the	O
C	B-Language
preprocessor	I-Language
macro	O
and	O
implements	O
runtime	O
assertion	O
in	O
C	O
.	O
</s>
<s>
assert.h	B-Language
is	O
defined	O
in	O
ANSI	O
C	O
as	O
part	O
of	O
the	B-Language
C	I-Language
standard	I-Language
library	I-Language
.	O
</s>
<s>
In	O
the	O
C++	B-Language
programming	I-Language
language	I-Language
,	O
assert.h	B-Language
and	O
are	O
available	O
;	O
both	O
are	O
functionally	O
equivalent	O
.	O
</s>
<s>
If	O
the	O
expression	O
within	O
it	O
is	O
false	O
,	O
the	O
macro	O
will	O
print	O
a	O
message	O
to	O
stderr	O
and	O
call	O
abort( )	O
,	O
defined	O
in	O
stdlib.h.	O
</s>
<s>
Since	O
C99	B-Language
,	O
the	O
name	O
of	O
the	O
function	O
the	O
assert	O
statement	O
is	O
included	O
as	O
(	O
)	O
and	O
the	O
expression	O
itself	O
.	O
</s>
<s>
In	O
C99	B-Language
,	O
the	O
macro	O
explicitly	O
allows	O
any	O
scalar	O
type	O
.	O
</s>
<s>
This	O
program	O
will	O
always	O
evaluate	O
as	O
false	O
,	O
as	O
is	O
a	O
null	O
pointer	O
and	O
does	O
not	O
point	O
to	O
a	O
valid	O
memory	B-General_Concept
location	I-General_Concept
:	O
</s>
<s>
The	O
macro	O
does	O
not	O
include	O
an	O
error	B-Error_Name
message	I-Error_Name
.	O
</s>
<s>
However	O
the	O
comma	B-Language
operator	I-Language
can	O
be	O
used	O
to	O
add	O
it	O
to	O
the	O
printed	O
expression	O
,	O
as	O
in	O
.	O
</s>
<s>
The	O
macro	O
,	O
added	O
in	O
C++11	B-Language
,	O
serves	O
a	O
similar	O
purpose	O
to	O
the	O
macro	O
.	O
</s>
<s>
Unlike	O
the	O
macro	O
,	O
runs	O
at	O
compile-time	B-Application
rather	O
than	O
at	O
runtime	O
.	O
</s>
<s>
In	O
C++17	B-Language
,	O
this	O
assertion	O
failure	O
message	O
was	O
made	O
optional	O
,	O
and	O
the	O
subsequent	O
message	O
is	O
omitted	O
if	O
not	O
specified	O
.	O
</s>
<s>
assert.h	B-Language
defines	O
as	O
an	O
alias	O
for	O
to	O
ensure	O
parity	O
with	O
C++	B-Language
.	O
</s>
<s>
In	O
C23	B-Language
,	O
was	O
renamed	O
to	O
and	O
the	O
string	O
literal	O
argument	O
was	O
made	O
optional	O
.	O
</s>
<s>
Gnulib	B-Application
defines	O
for	O
platforms	O
that	O
do	O
not	O
use	O
C11	O
and	O
does	O
not	O
require	O
to	O
be	O
included	O
.	O
</s>
