On Thu, 2023-02-09 at 14:56 +0000, Jonathan Wakely via Gcc-help wrote: > > Note, my code isn't like this, it is just an example to suggest > > adding the nullptr attribute, as its clearly already rejected at > > runtime. > > I assume you mean the nonnull attribute. That was added in 2020 and > then reverted because it broke some things: I remember I'd once made the same mistake when I suggested to add nonnull for ostream::operator<<(const string &) and I was lectured: nonnull is not only a diagnostic attribute, it also allows the compiler to assume the parameter is never null and rendering std::string(nullptr) an undefined behavior. Then the example may just silently continue to run, instead of throwing an exception. It would be an ironic example: an attempt to improve diagnostic finally made diagnostic more difficult. -- Xi Ruoyao <xry111@xxxxxxxxxxx> School of Aerospace Science and Technology, Xidian University
