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c++ Programming Glossary: nrvoC++ : Avoiding copy with the “return” statement http://stackoverflow.com/questions/10476665/c-avoiding-copy-with-the-return-statement can take advantage of named return value optimization NRVO . See here http en.wikipedia.org wiki Copy_elision In C 11 there..
Understanding return value optimization and returning temporaries - C++ http://stackoverflow.com/questions/1394229/understanding-return-value-optimization-and-returning-temporaries-c and most compilers supports it. The last case is so called NRVO Named RVO . That's relatively new feature of C . Standard allows.. C . Standard allows but doesn't require implementation of NRVO as well as RVO but some compilers supports it. You could read..
When should std::move be used on a function return value? http://stackoverflow.com/questions/14856344/when-should-stdmove-be-used-on-a-function-return-value were designated by an rvalue. return foo is a case of NRVO so copy elision is permitted. foo is an lvalue. So the constructor.. elided because return std move foo is not eligible for NRVO. As far as I know 12.8 32 lays out the only conditions under..
When is explicit move needed for a return statement? http://stackoverflow.com/questions/17481018/when-is-explicit-move-needed-for-a-return-statement as an rvalue if it is eligible for copy move elision aka NRVO but that is too restrictive because it means it only applies..
http://stackoverflow.com/questions/2025899/when-should-rvo-kick-in string str return str Not RVO A more general version is NRVO Named return value optimization which also works on named variables... std string foo std string str hello world bar return str NRVO std string foo std string str return str Not NRVO as far as.. str NRVO std string foo std string str return str Not NRVO as far as I know. The string is constructed outside the function..
Is it more efficient to return a const reference http://stackoverflow.com/questions/275795/is-it-more-efficient-to-return-a-const-reference inefficiency smart compilers may apply the RVO or the NRVO optimizations but there are cases in which they can't multiple..
Why isn't the copy constructor called here? [duplicate] http://stackoverflow.com/questions/4286301/why-isnt-the-copy-constructor-called-here return Base 5 int main Base b foo In the yet more generic NRVO Named return value optimization when processing the internal..
C++ performance challenge: integer to std::string conversion http://stackoverflow.com/questions/4351371/c-performance-challenge-integer-to-stdstring-conversion std string on each. VC2010 clearly does a better job with NRVO getting rid of return by value helped only on gcc. Code was..
Creating and returning a big object from a function http://stackoverflow.com/questions/4809120/creating-and-returning-a-big-object-from-a-function The optimization is called named return value optimization NRVO so it's okay to return big objects like that. The compiler can.. copy. Generally the compiler will always try to implement NRVO and or RVO although it may fail to do so in certain circumstances..
Are value parameters implicitly moved when returned by value? http://stackoverflow.com/questions/6009004/are-value-parameters-implicitly-moved-when-returned-by-value the copy constructor or the move constructor Let's leave NRVO aside here. To investigate I wrote a simple Foo class that is..
How to emulate C array initialization “int arr[] = { e1, e2, e3, … }” behaviour with std::array? http://stackoverflow.com/questions/6114067/how-to-emulate-c-array-initialization-int-arr-e1-e2-e3-behaviou make_array 1 2 3 However this requires the compiler to do NRVO and then also skip the copy of returned value which is also..
Is RVO (Return Value Optimization) applicable for all objects? http://stackoverflow.com/questions/7596183/is-rvo-return-value-optimization-applicable-for-all-objects return statement and well it is returned. In the case of NRVO you would have to analyze the code to understand whether the..
How to disable return value optimization in Visual Studio 2010? http://stackoverflow.com/questions/9941043/how-to-disable-return-value-optimization-in-visual-studio-2010 this question You cannot. It is just that simple. RVO NRVO is Standard and your code should not depend on it not being..
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