Declarations referenced in a dependent template argument may get removed

[AlCash07]

Example: http://ideone.com/QaLeKP

If I rewrite the function in the following way, everything works:
template <class Y> void f(Y& y) { typename Y::value_type value = 42; y.value = value; }

[AlCash07]

This issue is actually very important for template metaprogramming. The following example fails on multiple levels: https://ideone.com/8UCOkK