c++11 - C++ access rvalue referenced object from non rvalue object -

c++11 - C++ access rvalue referenced object from non rvalue object -

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most vexing parse: why doesn't a(()); work? 5 answers

this question may sound stupid. want create sure. , maybe point me described in standard.

we cannot have rvalue referenced objects within lvalue. right?

struct a{int value;}; struct b{ b(a &&value) : a(std::forward<a>(value)){} a&& a; }; int main() { // allowed b(a()).a; // error b b(a()); b.a; homecoming 0; }

http://coliru.stacked-crooked.com/a/ea6bd617d421a8b8

b b(a()); declares function (most vexing parse). compiler error because b has no fellow member a.

to prepare issue write b b{a()} instead.

c++ c++11 rvalue-reference