message: Warning and comment
diff: @@ -110,6 +110,12 @@ public:
  const size_t &operator[](size_t index) const { return DimensSpan[index]; }
  size_t &operator[](size_t index) { return DimensSpan[index]; }
  CoreDims() : DimCount(0), DimensSpan(NULL) {}
  +
  + // Warning!!! CoreDims is essentially a Span. It does not own the
  + // memory that its [] operators access. Users must ensure that
  + // memory remains valid as long as it is necessary. If you don't
  + // know the memory will be valid the entire time, use the
  + // DimsArray class which copies the dimension data.
  CoreDims(std::vector<size_t> vec)
  : DimCount(vec.size()), DimensSpan(vec.data())
  {
  @@ -119,7 +125,7 @@ public:
  {
  }
  - const size_t size() const { return DimCount; }
  + size_t size() const { return DimCount; }
  bool empty() const { return DimCount == 0; }
  // iterator
  typedef const size_t *const_iterator;
  