From 726c914ee556a29dcea5c497cbd30c8425ad655b Mon Sep 17 00:00:00 2001
From: Robert Maynard <robert.maynard@kitware.com>
Date: Tue, 16 Jun 2015 09:52:23 -0400
Subject: [PATCH] Make sure we use ptrdiff_t for index into arrays.

This is a requirement since you can use negative indices into arrays.
---
 vtkm/cont/internal/IteratorFromArrayPortal.h      | 2 +-
 vtkm/exec/cuda/internal/IteratorFromArrayPortal.h | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/vtkm/cont/internal/IteratorFromArrayPortal.h b/vtkm/cont/internal/IteratorFromArrayPortal.h
index 3f3a69138..55c70d386 100644
--- a/vtkm/cont/internal/IteratorFromArrayPortal.h
+++ b/vtkm/cont/internal/IteratorFromArrayPortal.h
@@ -107,7 +107,7 @@ public:
 
   VTKM_CONT_EXPORT
   detail::IteratorFromArrayPortalValue<ArrayPortalType>
-  operator[](std::size_t idx) const
+  operator[](std::ptrdiff_t idx) const //NEEDS to be signed
   {
     return detail::IteratorFromArrayPortalValue<ArrayPortalType>(this->Portal,
            this->Index + static_cast<vtkm::Id>(idx) );
diff --git a/vtkm/exec/cuda/internal/IteratorFromArrayPortal.h b/vtkm/exec/cuda/internal/IteratorFromArrayPortal.h
index ea319ec0a..637e0a836 100644
--- a/vtkm/exec/cuda/internal/IteratorFromArrayPortal.h
+++ b/vtkm/exec/cuda/internal/IteratorFromArrayPortal.h
@@ -113,7 +113,7 @@ public:
 
   VTKM_EXEC_EXPORT
   PortalValue<ArrayPortalType>
-  operator[](std::size_t idx) const
+  operator[](std::ptrdiff_t idx) const //NEEDS to be signed
   {
     return PortalValue<ArrayPortalType>(this->Portal,
            this->Index + static_cast<vtkm::Id>(idx) );