some enforce change

paddle/framework/lod_tensor.cc

@@ -72,18 +72,28 @@ bool operator==(const LoD& a, const LoD& b) {
   return true;
 }
 
+size_t LoDTensor::NumElements(size_t level, size_t idx) const {
+  PADDLE_ENFORCE_LT(level, NumLevels());
+  PADDLE_ENFORCE_LT(idx, NumElements(level));
+  // the last level of LoD, just return number of records in Tensor
+  if (level == NumLevels() - 1) {
+  }
+  // high level of LoD, and there is another lower level, return number of
+  // lower-level elements
+}
+
 void LoDTensor::SliceLevels(size_t level_begin, size_t level_end) {
   auto new_lod = framework::SliceLevels(lod_, level_begin, level_end);
   lod_ = new_lod;
 }
 
 void LoDTensor::SliceInLevel(size_t level, size_t elem_begin, size_t elem_end) {
-  PADDLE_ENFORCE(level < NumLevels(), "level [%d] out of range [%d]", level,
+  PADDLE_ENFORCE_LT(level, NumLevels(), "level [%d] out of range [%d]", level,
                     NumLevels());
-  PADDLE_ENFORCE(elem_begin < NumElements(level),
+  PADDLE_ENFORCE_LT(elem_begin, NumElements(level),
                     "element begin [%d] out of range [%d]", elem_begin,
                     NumElements(level));
-  PADDLE_ENFORCE(elem_end < NumElements(level) + 1,
+  PADDLE_ENFORCE_LT(elem_end, NumElements(level) + 1,
                     "element end [%d] out of range [%d]", elem_end,
                     NumElements(level));
 

paddle/framework/lod_tensor.h

@@ -65,11 +65,8 @@ class LoDTensor : public Tensor {
    * Get a element from LoD.
    */
   size_t lod_element(size_t level, size_t elem) const {
-    PADDLE_ENFORCE(level < NumLevels(), "level [%d] out of range [%d]", level,
-                   NumLevels());
-    PADDLE_ENFORCE(elem < NumElements(level),
-                   "element begin [%d] out of range [%d]", elem,
-                   NumElements(level));
+    PADDLE_ENFORCE_LT(level, NumLevels());
+    PADDLE_ENFORCE_LT(elem, NumElements(level));
     return (lod_)[level][elem];
   }
 
@@ -82,12 +79,23 @@ class LoDTensor : public Tensor {
    * Number of elements in a level.
    */
   size_t NumElements(size_t level = 0) const {
-    PADDLE_ENFORCE(level < NumLevels(), "level [%d] out of range [%d]", level,
-                   NumLevels());
+    PADDLE_ENFORCE_LT(level, NumLevels());
     // the last offset is the end of last element
     return (lod_)[level].size() - 1;
   }
 
+  /*
+   * Number of lower-level elements.
+   * For example, a 2-level lod-tensor
+   *
+   * 0-th level   |   |
+   * 1-th level   ||  |||
+   *
+   * NumElements(0, 0) get 2
+   * NumElements(0, 1) get 3
+   */
+  size_t NumElements(size_t level, size_t idx) const;
+
   /*
    * Slice of levels[level_begin:level_end]
    */