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1449. Incomplete specification of header<cinttypes>

Section: 31.8.3[istringstream]Status:C++11Submitter: CanadaOpened: 2010-08-25Last modified: 2016-01-28

Priority:Not Prioritized

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Discussion:

Addresses CA-4

Subclause 27.9.2 [c.files] specifies that <cinttypes> hasdeclarations for abs() and div(); however, the signaturesare not present in this subclause. The signaturesproposed under TR1 ([tr.c99.inttypes]) are not present inFCD (unless if intmax_t happened to be long long). It isunclear as to which, if any of the abs() and div() functionsin [c.math] are meant to be declared by <cinttypes>. Thissubclause mentions imaxabs() and imaxdiv(). Thesefunctions, among other things, are not specified in FCD tobe the functions from Subclause 7.8 of the C Standard.Finally, <cinttypes> is not specified in FCD to include<cstdint> (whereas <inttypes.h> includes <stdint.h> in C).

[Post-Rapperswil, Daniel provides wording]

Subclause [c.files] specifies that<cinttypes> has declarations forabs() anddiv(); however, the signatures are not present in this subclause. The signatures proposed under TR1 ([tr.c99.inttypes]) are not present in FCD (unless ifintmax_t happened to belong long). It is unclear as to which, if any of theabs() anddiv() functions in [c.math] are meant to be declared by<cinttypes>. Thissubclause mentionsimaxabs() andimaxdiv(). These functions, among other things, are not specified in FCD to be the functions from subclause 7.8 of theC Standard. Finally,<cinttypes> is not specified in FCD to include<cstdint> (whereas<inttypes.h> includes<stdint.h> inC).

Moved to Tentatively Ready with proposed wording after 5 positive votes on c++std-lib.

[Adopted at 2010-11 Batavia]

Proposed resolution:

The wording refers to N3126.

1. Add the following series of new paragraphs following [c.files] p.1:

   Table 132 describes header<cinttypes>. [Note: The macros defined by<cinttypes> are provided unconditionally.In particular, the symbol__STDC_FORMAT_MACROS, mentioned in footnote 182 of theC standard, plays no role inC++. —end note ]

   2 - The contents of header<cinttypes> are the same as the StandardC library header<inttypes.h>, with the following changes:

   3 - The header<cinttypes> includes the header<cstdint> instead of<stdint.h>.

   4 - If and only if the typeintmax_t designates an extended integer type ([basic.fundamental]), the following function signatures are added:

   intmax_t abs(intmax_t);imaxdiv_t div(intmax_t, intmax_t);

   which shall have the same semantics as the function signaturesintmax_t imaxabs(intmax_t) andimaxdiv_t imaxdiv(intmax_t, intmax_t), respectively.