[lex.icon] (original) (raw)

5 Lexical conventions [lex]

5.13 Literals [lex.literal]

5.13.2 Integer literals [lex.icon]

octal-digit: one of
0 1 2 3 4 5 6 7

nonzero-digit: one of
1 2 3 4 5 6 7 8 9

hexadecimal-prefix: one of
0x 0X

hexadecimal-digit: one of
0 1 2 3 4 5 6 7 8 9
a b c d e f
A B C D E F

unsigned-suffix: one of
u U

long-long-suffix: one of
ll LL

In an integer-literal, the sequence ofbinary-digits,octal-digits,digits, orhexadecimal-digit_s_is interpreted as a base N integer as shown in table Table 7; the lexically first digit of the sequence of digits is the most significant.

[Note 1:

The prefix and any optional separating single quotes are ignored when determining the value.

— _end note_]

The hexadecimal-digits a through f and A through Fhave decimal values ten through fifteen.

[Example 1:

The number twelve can be written 12, 014,0XC, or 0b1100.

The integer-literals 1048576,1'048'576, 0X100000, 0x10'0000, and0'004'000'000 all have the same value.

— _end example_]

The type of an integer-literal is the first type in the list in Table 8corresponding to its optional integer-suffixin which its value can be represented.

An integer-literal is a prvalue.

Table 8: Types of integer-literals [tab:lex.icon.type]

🔗	*integer-suffix*	*decimal-literal*	**integer-literal other than decimal-literal**
🔗	none	int	int
🔗	long int	unsigned int
🔗	long long int	long int
🔗	unsigned long int
🔗	long long int
🔗	unsigned long long int
🔗	u or U	unsigned int	unsigned int
🔗	unsigned long int	unsigned long int
🔗	unsigned long long int	unsigned long long int
🔗	l or L	long int	long int
🔗	long long int	unsigned long int
🔗	long long int
🔗	unsigned long long int
🔗	Both u or U	unsigned long int	unsigned long int
🔗	and l or L	unsigned long long int	unsigned long long int
🔗	ll or LL	long long int	long long int
🔗	unsigned long long int
🔗	Both u or U	unsigned long long int	unsigned long long int
🔗	and ll or LL

If an integer-literalcannot be represented by any type in its list and an extended integer type ([basic.fundamental]) can represent its value, it may have that extended integer type.

If all of the types in the list for the integer-literalare signed, the extended integer type shall be signed.

If all of the types in the list for the integer-literalare unsigned, the extended integer type shall be unsigned.

If the list contains both signed and unsigned types, the extended integer type may be signed or unsigned.

A program is ill-formed if one of its translation units contains an integer-literalthat cannot be represented by any of the allowed types.