change gridfn() and ghosted_gridfn() fns to return const references

for the rvalue case --> this makes them usable as the operand of a
unary-& (address-of) expression


git-svn-id: http://svn.einsteintoolkit.org/cactus/EinsteinAnalysis/AHFinderDirect/trunk@459 f88db872-0e4f-0410-b76b-b9085cfa78c5

1 files changed, 11 insertions, 10 deletions

diff --git a/src/patch/grid.hh b/src/patch/grid.hh
index a8220f4..b548297 100644
--- a/src/patch/grid.hh
+++ b/src/patch/grid.hh
@@ -314,33 +314,34 @@ public:
 	//
 	// ***** gridfns *****
 	//
+	// ... all these functions (even the rvalue ones) must return
+	//     references, to allow using  gridfn(...)  as the operand
+	//     of a unary & (address-of) operator
+	//
 public:
-
 	// access to nominal-grid gridfn data
-	// ... rvalue (may be slightly faster since it's a const function
-	//     and it returns by value rather than reference
-	fp  gridfn(int gfn,   int irho, int isigma) const
+	// ... rvalue
+	const fp& gridfn(int gfn,   int irho, int isigma) const
 		{
 		assert(gridfn_data_ != NULL);
 		return (*gridfn_data_)(gfn, irho, isigma);
 		}
-	// ... lvalue (must return a reference)
-	fp& gridfn(int gfn,   int irho, int isigma)
+	// ... lvalue
+	      fp& gridfn(int gfn,   int irho, int isigma)
 		{
 		assert(gridfn_data_ != NULL);
 		return (*gridfn_data_)(gfn, irho, isigma);
 		}
 
 	// access to ghosted-grid gridfn data
-	// ... rvalue (may be slightly faster since it's a const function
-	//     and it returns by value rather than reference
-	fp  ghosted_gridfn(int gfn,   int irho, int isigma) const
+	// ... rvalue
+	const fp& ghosted_gridfn(int gfn,   int irho, int isigma) const
 		{
 		assert(gridfn_data_ != NULL);
 		return (*ghosted_gridfn_data_)(gfn, irho, isigma);
 		}
 	// ... lvalue (must return a reference)
-	fp& ghosted_gridfn(int gfn,   int irho, int isigma)
+	      fp& ghosted_gridfn(int gfn,   int irho, int isigma)
 		{
 		assert(gridfn_data_ != NULL);
 		return (*ghosted_gridfn_data_)(gfn, irho, isigma);