Opened from comment 4 in PR29727.

The following valid snipped is rejected with the current mainline

===
template<int> struct A
{
  struct S { int X; };
  static S a;
};

template<int N> typename A<N>::S A<N>::a = { X : 1 };

void foo()
{
  A<0>::a;
}
===

because 'X' is not found in the designated initializer:

[...]
  pr29727_valid.C:18: error: 'Y' was not declared in this scope
  pr29727_valid.C:18: error: 'B<0>::S' has no non-static data member named '<declaration error>'


We get the same with 4.0.1, 4.2.1 and the 4.3 branch. I don't have any earlier version to check, so I don't know if this is a regression or not.

With a non template class, the code is accepted.