STYLE: simplify short-circuit involving autoPtr (#1775)

- with '&&' conditions, often better to check for non-null autoPtr
  first (it is cheap)

- check as bool instead of valid() method for cleaner code, especially
  when the wrapped item itself has a valid/empty or good.
  Also when handling multiple checks.

  Now
      if (ptr && ptr->valid())
      if (ptr1 || ptr2)

  instead
      if (ptr.valid() && ptr->valid())
      if (ptr1.valid() || ptr2.valid())

src/phaseSystemModels/reactingEulerFoam/derivedFvPatchFields/alphatWallBoilingWallFunction/alphatWallBoilingWallFunctionFvPatchScalarField.C

@@ -646,12 +646,12 @@ void alphatWallBoilingWallFunctionFvPatchScalarField::updateCoeffs()
 
             if
             (
-                CHFModel_.valid()
-                && CHFSoobModel_.valid()
-                && TDNBModel_.valid()
-                && MHFModel_.valid()
-                && LeidenfrostModel_.valid()
-                && filmBoilingModel_.valid()
+                CHFModel_
+             && CHFSoobModel_
+             && TDNBModel_
+             && MHFModel_
+             && LeidenfrostModel_
+             && filmBoilingModel_
             )
             {
 

src/phaseSystemModels/reactingEulerFoam/phaseSystems/BlendedInterfacialModel/BlendedInterfacialModel.C

@@ -6,6 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2014-2018 OpenFOAM Foundation
+    Copyright (C) 2020 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -106,7 +107,7 @@ Foam::BlendedInterfacialModel<ModelType>::evaluate
 
     tmp<scalarGeoField> f1, f2;
 
-    if (model_.valid() || model1In2_.valid())
+    if (model_ || model1In2_)
     {
         f1 =
             blendedInterfacialModel::interpolate<scalarGeoField>
@@ -115,7 +116,7 @@ Foam::BlendedInterfacialModel<ModelType>::evaluate
             );
     }
 
-    if (model_.valid() || model2In1_.valid())
+    if (model_ || model2In1_)
     {
         f2 =
             blendedInterfacialModel::interpolate<scalarGeoField>
@@ -177,7 +178,7 @@ Foam::BlendedInterfacialModel<ModelType>::evaluate
     if
     (
         correctFixedFluxBCs_
-     && (model_.valid() || model1In2_.valid() || model2In1_.valid())
+     && (model_ || model1In2_ || model2In1_)
     )
     {
         correctFixedFluxBCs(x.ref());
@@ -300,8 +301,8 @@ bool Foam::BlendedInterfacialModel<ModelType>::hasModel
 {
     return
        &phase == &(phase1_)
-      ? model1In2_.valid()
-      : model2In1_.valid();
+      ? bool(model1In2_)
+      : bool(model2In1_);
 }