Annex G (informative) Ill-formed, no diagnostic required [ifndr]

G.10 [temp]: Templates [ifndr.temp]

G.10.7[ifndr:temp.over.link.equiv.not.equiv]
Specified in: [temp.over.link]

1
#
If the validity or meaning of the program depends on whether two constructs are equivalent, and they are functionally equivalent but not equivalent, the program is ill-formed, no diagnostic required.
2
#
[Example 1: template <int I> struct A{}; // IFNDR, the following declarations are functionally equivalent but not equivalent template <int I> void f(A<I>, A<I+10>); template <int I> void f(A<I>, A<I+1+2+3+4>); — end example]