小编Leo*_*nid的帖子

以下哪些是不确定的行为：

template <class T> struct Struct { T t; };

template <class T> union Union { T t; };

template <class T> void function() {
  Struct aS[10];
  Union aU[10];

  // do something with aS[9].t and aU[9].t including initialization

  T *aSP = reinterpret_cast<T *>(aS);
  T *aUP = reinterpret_cast<T *>(aU);

  // so here is this undefined behaviour?
  T valueS = aSP[9];
  // use valueS in whatever way

  // so here is this undefined behaviour?
  T valueU = aUP[9];
  // use valueU in …