https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110912
--- Comment #2 from Jan Schultke <janschultke at googlemail dot com> --- (In reply to Jiang An from comment #1) > The restriction agains aliasing was intended, see > https://cplusplus.github.io/CWG/issues/2271.html. > > The status quo seems to be that in the body of `A::A(int &x)`, compilers can > assume that the value of `x` won't be changed by a modification on `*this`, > but not the other way around. Then this status quo is not correctly implemented, because in the example, GCC assumes that a change of `x` (see `x = 5`) cannot alter `this->i` (see `i == 0` assumed to be always true). It is not enough to put `__restrict` on the parameters; a much weaker modifier must be used for this purpose. At most, a "one-way `__restrict`" must be used, if such a thing exists.
