c++ - Are return types considered as rvalues? -

just simple question, trying simulate bad practice when comes returning &&. aware it's bad practice.

here example

//dummy empty class dummy && crashtest(){     dummy temp;     return std::move(temp);  }   int main() {     dummy && k = crashtest();     return 0; } 

this bad practice because k holds reference destructed temp inside function.

i tried different approach doing inside main:

dummy l; //generate temp dummy && k =  std::move(l); //return value dummy && d = k; // copy 

though l won't destroyed, how come won't let me compile? error saying trying bind lvalue. isn't same happens in function? understanding, happened in function was:

temp created -> std::move(temp) -> return type dummy&& receives -> k equalized return type temporary.

i need clarification. return type considered rvalue ?

bonus question: happens if rvalue reference variable equalized rvalue reference variable? &&lhs = &&rhs, lhs takes rhs reference?

returning rvalue reference function cause dangling reference(the reference exists, temporary object refers has been destroyed). called xvalue(an "expiring" value) in standard.