From 964610fc497e888c07e0009019442f41bf5ab934 Mon Sep 17 00:00:00 2001
From: Tobias Meyer Andersen <tobiasmeyer.andersen@sintef.no>
Date: Thu, 11 Dec 2025 09:42:00 +0100
Subject: [PATCH] add fsys ptr getter

---
 opm/material/fluidstates/BlackOilFluidState.hpp | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/opm/material/fluidstates/BlackOilFluidState.hpp b/opm/material/fluidstates/BlackOilFluidState.hpp
index 71fe7587ff2..088e5fa0351 100644
--- a/opm/material/fluidstates/BlackOilFluidState.hpp
+++ b/opm/material/fluidstates/BlackOilFluidState.hpp
@@ -706,6 +706,17 @@ class BlackOilFluidState
         }
     }
 
+    /// \brief Return a pointer to the fluid system used by this fluid state.
+    OPM_HOST_DEVICE FluidSystem const* fluidSystemPtr() const
+    {
+        if constexpr (fluidSystemIsStatic) {
+            static FluidSystem instance;
+            return &instance;
+        } else {
+            return fluidSystemPtr_;
+        }
+    }
+
 private:
     OPM_HOST_DEVICE static unsigned storageToCanonicalPhaseIndex_(unsigned storagePhaseIdx, const FluidSystem& fluidSystem)
     {