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- What are copy elision and return value optimization?
Copy elision is an optimization implemented by most compilers to prevent extra (potentially expensive) copies in certain situations It makes returning by value or pass-by-value feasible in practice (restrictions apply)
- c++ - How does guaranteed copy elision work? - Stack Overflow
Copy elision was permitted to happen under a number of circumstances However, even if it was permitted, the code still had to be able to work as if the copy were not elided Namely, there had to be an accessible copy and or move constructor Guaranteed copy elision redefines a number of C++ concepts, such that certain circumstances where copies moves could be elided don't actually provoke a
- Why does std::move prevent RVO (return value optimization)?
Copy elision (the mechanism behind RVO) is permitted only under certain, strict conditions Writing std::move prevents those conditions from being met
- c++ - std::move versus copy elision - Stack Overflow
The hint is still correct though, since std::move on a temporary either doesn't have any effect at all (as here) or prevents elision if used in a context where copy elision would otherwise be allowed mandatory, for example if this was the initializer of m_thread instead of an assignment to it
- c - Enable Disable Hardware Lock Elision - Stack Overflow
It has lock elision path included for pthread_mutex_lock implementation with Transactional Synchronization Extensions such as _xbegin () and _xend () The hardware is supposed to support lock elision as hle CPU flag is for Hardware Lock Elision I think
- What is copy elision and how does it optimize the copy-and-swap idiom?
One to construct newcounter and the other to construct tmp And without copy elision there would still be 3 That's why declaring operator = so its argument requires invoking the copy construct can be an optimization when using the 'copy and swap' idiom for the assignment operator
- c++ Moving a temporary object prevents copy elision (fix available . . .
Moving a temporary object prevents copy elision (fix available)clang(-Wpessimizing-move) I am using clang-14 and vscode, vscode's quick fix let me delete std::move, but why? As far as i know, unique_ptr can't be passed as a parameter directly
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