On Nov 3, 2015, at 1:10 PM, Martin Sebor <mse...@gmail.com> wrote: > The "as if" requirement implies that any observable effects of > "the (possibly replaced) ordinary version" must be preserved. > The repeated calls to the new handler are among such effects.
Unless the standard is fixed to say that one cannot observe the repeated calls. We do this in some places, for some things: 15Whenever a temporary class object is copied using a copy constructor, and this object and the copy have the same cv-unqualified type, an implementation is permitted to treat the original and the copy as two different ways of referring to the same object and not perform a copy at all, even if the class copy constructor or destructor have side effects. For a function with a class return type, if the expression in the return statement is the name of a local object, and the cv- unqualified type of the local object is the same as the function return type, an implementation is permitted to omit creating the tem- porary object to hold the function return value, even if the class copy constructor or destructor has side effects. In these cases, the object is destroyed at the later of times when the original and the copy would have been destroyed without the optimization.111) in C++, so, it isn’t out of the question. I was looking for dynamic -> static object optimization wording, but didn’t find it in the first C++ standard. That is a fairly reasonable thing to do, and if done well, can reasonably change the observable side-effects as well.
