[Development] Qt 5.9's new garbage collector documentation? + root_ptr

[Tim Blechmann]

> - the parameters of the function will remain unaffected if they are used as r-values
> - the parameters of the function will require a deep copy of the expression if they are used as l-values 

https://en.wikipedia.org/wiki/Evaluation_strategy#Call_by_sharing


function foo( arg )
{
  var img = readImage( arg.source );
  arg.result = img;
  return img;
}

required semantics: arg.result and the return value refer to the same
object.

--

btw, it may be interesting for you to read a bit about escape analysis.