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charset="us-ascii" Content-ID: <0BA5F9DF9BD7E146910444CC8FA0AC64@namprd19.prod.outlook.com> Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: Dell.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: SA0PR19MB4508.namprd19.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: 1265e6a7-a52d-441c-be5c-08da8a8c1ba4 X-MS-Exchange-CrossTenant-originalarrivaltime: 30 Aug 2022 13:32:38.9557 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 945c199a-83a2-4e80-9f8c-5a91be5752dd X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: 4jB7xhaSB0NASA/JnnfULNWUHJmoRbGTKuJO9EHNTK7g51IUZdsVN39cM2IDmvJ7juPVCFL1l0ZZUOQM1IK4lQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS7PR19MB5711 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.517,FMLib:17.11.122.1 definitions=2022-08-30_08,2022-08-30_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 phishscore=0 spamscore=0 mlxscore=0 suspectscore=0 priorityscore=1501 malwarescore=0 bulkscore=0 clxscore=1011 mlxlogscore=999 adultscore=0 impostorscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2207270000 definitions=main-2208300067 X-Proofpoint-ORIG-GUID: -af6_K0_vDV4NCFoaRMOg0qjm6Ogz6o4 X-Proofpoint-GUID: -af6_K0_vDV4NCFoaRMOg0qjm6Ogz6o4 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 spamscore=0 phishscore=0 malwarescore=0 mlxscore=0 suspectscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2207270000 definitions=main-2208300067 X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE,TXREP,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: > On Aug 30, 2022, at 9:22 AM, Jason Merrill via Gcc-patches wrote: >=20 > On 7/13/22 15:29, Nathan Sidwell wrote: >> Inspired by a user question. Jason, thoughts? >> Since C++ is such a moving target, Microsoft have /std:c++latest >> (AFAICT clang does not), to select the currently implemented version >> of the working paper. But the use of 'std:latest' is somewhat >> ambiguous -- the current std is C++20 -- that's the latest std, the >> next std will more than likely but not necessarily be C++23. So this >> adds: >> -std=3Dc++current -- the current std (c++20) >> -std=3Dc++future -- the working paper (c++2b) >> also adds gnu++current and gnu++future to select the gnu-extended >> variants. >=20 > I like this direction. >=20 > I imagine people using these to mean roughly beta and alpha, respectively= . >=20 > Perhaps we also want -std=3Dc++stable, which would currently be equivalen= t to the default (c++17) but might not always be. >=20 > Jason I'm not so sure. In general, switches have a fixed meaning. These do not. "Current" has an= intuitive meaning, but the actual meaning is "whatever what current when t= he version you happen to be invoking was released". "Future" is like that = only stranger. If I create a software package that uses one of these switches in its Makef= ile, what will happen? In a few years, perhaps sooner, the outcome will ch= ange without any changes to my code. The answer would be "don't use those = switches", and that is a good answer, but if so why add these switches? paul