This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 114b. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.

2024-05-06


2652. Overbroad definition of __STDCPP_BFLOAT16_T__

Section: 15.11  [cpp.predefined]     Status: C++23     Submitter: US     Date: 2022-11-03

P2720R0 comment US 31-071

[Accepted at the November, 2022 meeting.]

The wording for the predefined macro __STDCPP_BFLOAT16_T__ added by P1467 can be interpreted more broadly than was intended.

Proposed resolution (approved by CWG 2022-11-08):

Change in 15.11 [cpp.predefined] paragraph 1 as follows:

__STDCPP_BFLOAT16_T__

Defined as the integer literal 1 if and only if the implementation supports an extended floating-point type with the properties of the typedef-name std::bfloat16_t as described in 6.8.3 [basic.extended.fp].