big improvement of the block-manipulation API

- reduction of sizeof(Block) for vector types
- variants of block() and fixedBlock() for vector blocks
- convenience methods start() and end() for vectors
- convenience method corner() for matrices

1 files changed, 2 insertions, 0 deletions

diff --git a/Eigen/src/Core/Util.h b/Eigen/src/Core/Util.h
index 935a3dea6..8104201e6 100644
--- a/Eigen/src/Core/Util.h
+++ b/Eigen/src/Core/Util.h
@@ -94,6 +94,8 @@ const int Dynamic = -10;
 const int ColumnMajor = 0;
 const int RowMajor = 1;
 
+enum CornerType { TopLeft, TopRight, BottomLeft, BottomRight };
+
 //classes inheriting NoOperatorEquals don't generate a default operator=.
 class NoOperatorEquals
 {