Assert to avoid future surprises.

Well types must be either INJECTOR or PRODUCER for now, if
we change this in the future, we should check this part of
the code as well.

opm/core/simulator/WellState.hpp

@@ -23,6 +23,7 @@
 #include <opm/core/wells.h>
 #include <opm/core/well_controls.h>
 #include <vector>
+#include <cassert>
 
 namespace Opm
 {
@@ -45,6 +46,7 @@ namespace Opm
                 bhp_.resize(nw);
                 wellrates_.resize(nw * np, 0.0);
                 for (int w = 0; w < nw; ++w) {
+                    assert((wells->type[w] == INJECTOR) || (wells->type[w] == PRODUCER));
                     const WellControls* ctrl = wells->ctrls[w];
                     // Initialize bhp to be target pressure if
                     // bhp-controlled well, otherwise set to a little