Исходное сообщение
"Выпуск языка программирования Rust 1.40" Отправлено Урри, 23-Дек-19 14:33
.. который до сих пор даже студия не умеет скипать при дебаге; да и вообще: Access overhead: In pImpl, each call to a private member function indirects through a pointer. Each access to a public member made by a private member indirects through another pointer. Both indirections cross translation unit boundaries and so can only be optimized out by link-time optimization. Note that OO factory requires indirection across translation units to access both public data and implementation detail, and offers even fewer opportunities for the link time optimizer due to virtual dispatch. Space overhead: pImpl adds one pointer to the public component and, if any private member needs access to a public member, another pointer is either added to the implementation component or passed as a parameter for each call to the private member that requires it. If stateful custom allocators are supported, the allocator instance also has to be stored. Lifetime management overhead: pImpl (as well as OO factory) place the implementation object on the heap, which imposes significant runtime overhead at construction and destruction. This may be partially offset by custom allocators, since allocation size for pImpl (but not OO factory) is known at compile time.