Hi! Just for completeness:
On Fri, Mar 20, 2015 at 09:56:52PM +0100, Marek Polacek wrote: > +constexpr char d1 = *(&s[4] - 0); // { dg-error "array subscript out of > bound" } > +constexpr char d2 = *(&s[4] - 1); > +constexpr char d3 = *(&s[4] - 2); > +constexpr char d4 = *(&s[4] - 3); > +constexpr char d5 = *(&s[4] - 4); > +constexpr char d6 = *(&s[4] - 5); // { dg-error "negative array subscript" } > + > +/* Don't accept invalid stuff. */ > +constexpr char e1 = *(&s[5] - 1); // { dg-error "is not a constant > expression" } > +constexpr char e2 = *(&s[5] - 2); // { dg-error "is not a constant > expression" } > +constexpr char e3 = *(&s[5] - 3); // { dg-error "is not a constant > expression" } > + > +SA (c1 == 'a'); > +SA (c2 == 'b'); > +SA (c3 == 'b'); > +SA (c4 == 'c'); > +SA (c5 == 'c'); > +SA (c6 == 'c'); > +SA (c7 == '\0'); Miss SA here for d2-d5. > +constexpr char j1 = *(&l[4] - 0); // { dg-error "array subscript out of > bound" } > +constexpr char j2 = *(&l[4] - 1); > +constexpr char j3 = *(&l[4] - 2); > +constexpr char j4 = *(&l[4] - 3); > +constexpr char j5 = *(&l[4] - 4); > +constexpr char j6 = *(&l[4] - 5); // { dg-error "negative array subscript" } > +SA (i1 == 'c'); > +SA (i2 == 'd'); > +SA (i3 == 'd'); > +SA (i4 == 'e'); > +SA (i5 == 'e'); > +SA (i6 == 'e'); > +SA (i7 == '\0'); And SA here for j2-j5. Jakub