C++26: I-Std:Ingaphakathi_kwempilo

\u003ch2\u003eC++26: Std:Is_within_lifetime\u003c/h2\u003e \u003cp\u003eLe ndatshana ihlinzeka ngemininingwane ebalulekile nolwazi ngesihloko sayo, okunikela ekwabelaneni ngolwazi nasekuqondeni.\u003c/p\u003e \u003ch3\u003eOkuthathayo Okubalulekile\u003c/h3\u003e \u003cp\u003eAbafundi bangalindela ukuzuza:\u003c/p\u003e \u003cul\u003e \u003cli\u003eUkuqonda okujulile kwesihloko\u003c/li\u003e \u003cli\u003eIzinhlelo zokusebenza ezisebenzayo nokuhambisana komhlaba wangempela\u003c/li\u003e \u003cli\u003e Imibono yochwepheshe nokuhlaziya\u003c/li\u003e \u003cli\u003e Ulwazi olubuyekeziwe lwentuthuko yamanje\u003c/li\u003e \u003c/ul\u003e \u003ch3\u003eValue Proposition\u003c/h3\u003e \u003cp\u003e Okuqukethwe kwekhwalithi okufana nalokhu kusiza ekwakheni ulwazi futhi kukhuthaze ukuthathwa kwezinqumo unolwazi ezizindeni ezihlukahlukene.\u003c/p\u003e

Imibuzo Evame Ukubuzwa

Iyini i-std::is_within_lifetime futhi kungani yethulwa ku-C++26?

I-

std::is_within_lifetime iyingqikithi yesikhathi sokuhlanganisa entsha eyethulwe ku-C++26 enquma ukuthi isikhombisi esinikeziwe sibhekisela entweni okwamanje ephakathi nesikhathi sokuphila kwayo phakathi nokuhlolwa okuqhubekayo. Yethulwe ukuze kuxazululwe igebe eselivele likhona kuhlelo lwe-constexpr, lapho onjiniyela babengenandlela ephephile, ephathekayo yokuthola ukufinyelela kwesikhombi okungase kube okungavumelekile phakathi nokuhlanganisa isikhathi sokubala, okunika amandla ikhodi ye-constexpr eqinile futhi ecacile ngaphandle kokuncika ekuziphatheni okungachazwanga.

Ihluke kanjani i-std::is_within_lifetime ekuhloleni okukhona kokufaneleka kwezikhombisi?

Ngokungafani nokuhlolwa kwesikhathi sokusebenza okufana nokuqhathanisa kwezikhombi ezingenalutho noma amathuluzi e-sanitizer, i-std::is_within_lifetime isebenza ngokukhethekile ngaphakathi kokuqukethwe okuhlolwa njalo. Akuwona umsebenzi wesikhathi sokusebenza — awukwazi ukubizwa ngekhodi evamile yesikhathi sokusebenza. Lokhu kuyenza ihluke kakhulu kumathuluzi afana ne-AddressSanitizer, asebenza ngemva kokuhlanganiswa. Inikeza umhlanganisi ngokwakhe igunya lokuphendula imibuzo yempilo yonke, okwenza constexpr uhlobo lwe-punning olusekelwe kunyunyana kanye namaphethini afanayo ekugcineni achazwe kahle futhi ahloleke.

Iziphi izimo zokusebenzisa ezingokoqobo std::is_within_lifetime ezivulela onjiniyela be-C++?

Isimo esisetshenziswa ngokushesha sisebenzisa i-constexpr-friendly std::optional kanye std::variant ngaphandle kokugebenga. Onjiniyela manje bangahlola ngokuphephile ukuthi ilungu elisebenzayo lenyunyana livumelekile yini phakathi nokuhlolwa kwesikhathi sokuhlanganisa. Emaqenjini akha ithuluzi lesimanje le-C++, imitapo yolwazi, noma izinkundla — njengalezo ezihlanganisa ukugeleza komsebenzi wokuthuthukisa nge-Mewayz (amamojula angu-207, aqala ku-$19/mo) — lesi sici sehlisa kakhulu izingozi zokuziphatha ezingachazwanga kuzisekelo zekhodi ezisindayo zesifanekiso.

Ingabe i-std::is_within_lifetime iyasekelwa kuzo zonke izihlanganisi ezinkulu eceleni kwezinye izici ze-C++26?

Kusukela ekuqaleni kuka-2026, usekelo lwe-compiler lwe-std::is_within_lifetime lusaqhubeka. I-GCC ne-Clang inosekelo lokuhlola lwe-C++26 olunikwe amandla ngamafulegi -std=c++26, anesici esitholakalayo esingaphelele. I-MSVC iphinde iqhubekele phambili ngomgwaqo wayo we-C++26. Onjiniyela bayelulekwa ukuthi bahlole amamakhro wokuhlola isici se-compiler (__cpp_lib_is_within_lifetime) ngaphambi kokusetshenziswa. Ukuhlala unolwazi ngezibuyekezo ze-toolchain kanye nokuhlunga indawo yakho ye-dev - okuthile kweplathifomu efana ne-Mewayz ehamba phambili kuwo wonke amamojula awo angu-207 - ihlala ibalulekile.