What are copy elision and return value optimization?
2012年10月18日 · 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 …
optimization - How to allow copy elision construction for C
Copy elision is an optimization, and is never guaranteed anyway. Yes, sometimes move semantics don't help because there isn't a cheap move operation, but in general I wouldn't …
c++ - How to disable copy elision for constructors with std::source ...
2021年8月26日 · Except, I run into the copy elision which almost beats the purpose of using std::source_location. I'd like my source_location to be the location at which the caller variable …
c++17 - C++ copy elision of fields - Stack Overflow
That has nothing to do with copy elision in function returns, all of this happens in the (eventual) construction of B. Nothing in the standard allows eliding (as in "breaking the as-if rule for") the …
c++ - Why doesn't "Guaranteed Copy Elision" mean that …
2022年11月24日 · Firstly, I've heard that Guaranteed Copy Elision is a misnomer (as, I currently understand, it's more about fundamentally redefining the fundamental value categories, r/l …
Copy elision, std::move, and chained function calls
2018年8月2日 · Copy elision is the technique the compiler uses to prevent unneeded copies. Basically, it preallocates memory outside of the function and passes it in to be used. In case of …
c++ - Mandatory copy elision? gcc 5.4.1 - Stack Overflow
2017年1月4日 · Copy elision is an optional optimization until C++17, and even in C++17 it is only mandatory in certain cases. As far as I remember, (N)RVO copy elision is not mandatory even …
Is C++17 copy elision applied to placement new? - Stack Overflow
2020年3月21日 · Guaranteed elision (aka: C++17's definition of prvalues) applies to the initialization of any object of type T with a prvalue of the same type. That includes objects …
Is there a way to disable copy elision in c++ compiler
2018年6月13日 · In c++98, the following program is expected to call the copy constructor. #include <iostream> using namespace std; class A { public: A() { cout << "default" ; } A(int …
Is this code well-defined regardless of copy elision?
2015年10月23日 · Elision is the merging of object lifetimes and identities. Elision can occur between a temporary (anonymous object) and the named object it is used to (directly) …