This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 118f. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.
2025-11-07
[Accepted as a DR at the June, 2023 meeting.]
Subclause 5.13.2 [lex.icon] paragraph 4 specifies:
If aninteger-literal cannot be represented by any type in itslist and an extended integer type (6.9.2 [basic.fundamental]) canrepresent its value, it may have that extended integer type. If all ofthe types in the list for theinteger-literal are signed, theextended integer type shall be signed. If all of the types in the listfor theinteger-literal are unsigned, the extended integer typeshall be unsigned. If the list contains both signed and unsignedtypes, the extended integer type may be signed or unsigned. A programis ill-formed if one of its translation units containsaninteger-literal that cannot be represented by any of theallowed types.
This implies that aninteger-literal with azsuffix can be of extended integer type, if the literal is larger thanwhat is representable instd::size_t.
According to the author of the paperP0330R8(Literal Suffix for (signed) size_t) introducing the feature, this isunintentional;z should only yieldstd::size_t andits corresponding signed integer type.
See also the corresponding WG14 paperN2998Literal Suffixes for size_t.
Proposed resolution (reviewed by CWG 2023-03-03, approved by CWG 2023-05-12):
Change in 5.13.2 [lex.icon] paragraph 4 as follows:
IfExcept forinteger-literals containingasize-suffix, if the value of aninteger-literalcannot be represented by any type in its list and an extended integertype (6.9.2 [basic.fundamental]) can represent its value, it may havethat extended integer type. If all of the types in the list fortheinteger-literal are signed, the extended integer typeshall beis signed. If all of the types in thelist for theinteger-literal are unsigned, the extended integertypeshall beis unsigned. If the list containsboth signed and unsigned types, the extended integer type may besigned or unsigned.A program is ill-formed if one of itstranslation units containsIf aninteger-literalthatcannot be represented by anyof the allowed types, the program is ill-formed.[ Note: Aninteger-literal with az orZsuffix is ill-formed if it cannot be represented bystd::size_t. -- end note ]
Additional notes (February, 2023)
Alerted the chair of SG22 (C/C++ Liaison).
Forwarded to EWG at the request of the EWG chair viacplusplus/papers#1467.
EWG 2023-05-11
The "z" suffixes meanstd::size_t (or its correspondingsigned type) only. The proposed resolution is accepted by EWG.