5 Lexical conventions [lex]

5.11 Keywords [lex.key]

The identifiers shown in Table 5 are reserved for use as keywords (that is, they are unconditionally treated as keywords in phase 7) except in an attribute-token.
Note
:
The register keyword is unused but is reserved for future use.
— end note
 ]
Table 5: Keywords   [tab:lex.key]
alignas
constinit
false
public
true
alignof
const_­cast
float
register
try
asm
continue
for
reinterpret_­cast
typedef
auto
co_­await
friend
requires
typeid
bool
co_­return
goto
return
typename
break
co_­yield
if
short
union
case
decltype
inline
signed
unsigned
catch
default
int
sizeof
using
char
delete
long
static
virtual
char8_­t
do
mutable
static_­assert
void
char16_­t
double
namespace
static_­cast
volatile
char32_­t
dynamic_­cast
new
struct
wchar_­t
class
else
noexcept
switch
while
concept
enum
nullptr
template
const
explicit
operator
this
consteval
export
private
thread_­local
constexpr
extern
protected
throw
Furthermore, the alternative representations shown in Table 6 for certain operators and punctuators ([lex.digraph]) are reserved and shall not be used otherwise:
Table 6: Alternative representations   [tab:lex.key.digraph]
and
and_­eq
bitand
bitor
compl
not
not_­eq
or
or_­eq
xor
xor_­eq