TVecSmallInt.SetSubRange Method

TVecSmallInt Class

Overload List

#SignatureDescription
1void SetSubRange(TMtxVecInt Src)Defines the calling vector to have the view of the same memory as Src.
2void SetSubRangeSets the subarray size to full size.
└ indexed: void SetSubRange(Int32 Index, Int32 Len)
3void SetSubRange(TMtxVecBase Src, Int32 Index, Int32 Len)Define a subvector of the Src vector.

Overload 1: void SetSubRange(TMtxVecInt Src)

Defines the calling vector to have the view of the same memory as Src.

#NameTypeDescription
1SrcTMtxVecIntsource TVecInt or TMtxInt

Result: stored in self (calling object)

Remarks:

Src vector's Length property may not change while any other object has it's own view of it.

a.SetSubRange(b,..);

This SetSubRange method must be handled with great care. Namely:

  • b can be freed before "a" and accessing "a" gives AV.
  • a can be further subranged with c and same problem occurs when b is freed before c.
  • If you resize b, all objects which have subranged b are no longer pointing to valid memory.
  • b can Subrange other objects. Similar problem as when changing the size of b. Again all objects which have subranged b are not longer pointing to valid memory.

All this can lead to hard to find bugs.

Overload 2: void SetSubRange

Sets the subarray size to full size.

Result: stored in self (calling object)

Remarks:

This method is the same as the Dew.Math.TMtxVecBase.SetFullRange method.

Indexed: void SetSubRange(Int32 Index, Int32 Len)

Defines a sub vector/matrix.

#NameTypeDescription
1IndexInt32start index
2LenInt32element count

Result: stored in self (calling object)

Remarks:

The method will define a subarray starting at Index and ending at Index+Len-1. No copying will occur, only pointers will be shifted or indices adjusted.

All values of the original Dew.Math.TMtxVecBase will be preserved. An exception will be raised, if an attempt is made to change the size of calling object.

A sub-vector/matrix is vector/matrix which does not neccessarily have its own memory allocated. Instead it adopts the memory of the source object and all operations done on the either of the objects affect the same elements. The use of subvectors/submatrices increases CPU cache reuse, lower's memory requirements, increases application performance and improves code readability.

To again obtain a view of the full vector/matrix, see Dew.Math.TMtxVecBase.SetFullRange

Overload 3: void SetSubRange(TMtxVecBase Src, Int32 Index, Int32 Len)

Define a subvector of the Src vector.

#NameTypeDescription
1SrcTMtxVecBasesource TVec, TMtx, TVecInt or TMtxInt
2IndexInt32start index
3LenInt32element count

Result: stored in self (calling object)

Remarks:

The method will define a subarray starting at Index and ending at Index+Len-1 of Src. No copying will occur, only pointers will be shifted or indices adjusted.

A sub-vector/matrix is vector/matrix which does not neccessarily have its own memory allocated. Instead it adopts the memory of the source object and all operations done on the either of the objects affect the same elements. The use of subvectors/submatrices increases CPU cache reuse, lower's memory requirements, increases application performance and improves code readability.

All values of the original Dew.Math.TMtxVecBase will be preserved. An exception will be raised, if an attempt is made to change the size of calling object. No exception will be raised, if Src is resized while subranged. (possibly leading to memory overwrites)

To again obtain a view of the original vector/matrix, call Dew.Math.TMtxVecBase.SetFullRange