ENH: simplify construction of zero-sized Clouds

- use Foam::zero as a dispatch tag

FIX: return moleculeCloud::constProps() List by reference not copy

STYLE: range-for when iterating cloud parcels

STYLE: more consistent typedefs / declarations for Clouds

applications/utilities/parallelProcessing/redistributePar/parLagrangianDistributor.C

@@ -227,19 +227,21 @@ Foam::parLagrangianDistributor::distributeLagrangianPositions
     pBufs.finishedSends();
 
 
+    // The cloud name
+    const word cloudName = lpi.name();
+
     {
         // Temporarily rename original cloud so we can construct a new one
         // (to distribute the positions) without getting a duplicate
         // registration warning
-        const word cloudName = lpi.name();
         lpi.rename(cloudName + "_old");
 
-        // New cloud on tgtMesh
+        // New empty cloud on tgtMesh
         passivePositionParticleCloud lagrangianPositions
         (
             tgtMesh_,
-            cloudName,
-            IDLList<passivePositionParticle>()
+            Foam::zero{},
+            cloudName
         );
 
         // Retrieve from receive buffers
@@ -310,11 +312,11 @@ Foam::parLagrangianDistributor::distributeLagrangianPositions
         //        ).objectPath()
         //    );
         //}
-
-        // Restore cloud name
-        lpi.rename(cloudName);
     }
 
+    // Restore cloud name
+    lpi.rename(cloudName);
+
 
     // The constructMap is in linear (processor) order
     return autoPtr<mapDistributeBase>::New

applications/utilities/parallelProcessing/redistributePar/passivePositionParticleCloud.C

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2017 OpenCFD Ltd.
+    Copyright (C) 2017-2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -34,6 +34,7 @@ namespace Foam
     defineTemplateTypeNameAndDebug(Cloud<passivePositionParticle>, 0);
 }
 
+
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
 Foam::passivePositionParticleCloud::passivePositionParticleCloud
@@ -52,15 +53,4 @@ Foam::passivePositionParticleCloud::passivePositionParticleCloud
 }
 
 
-Foam::passivePositionParticleCloud::passivePositionParticleCloud
-(
-    const polyMesh& mesh,
-    const word& cloudName,
-    const IDLList<passivePositionParticle>& particles
-)
-:
-    Cloud<passivePositionParticle>(mesh, cloudName, particles)
-{}
-
-
 // ************************************************************************* //

applications/utilities/parallelProcessing/redistributePar/passivePositionParticleCloud.H

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2017-2019 OpenCFD Ltd.
+    Copyright (C) 2017-2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -34,8 +34,8 @@ SourceFiles
 
 \*---------------------------------------------------------------------------*/
 
-#ifndef passivePositionParticleCloud_H
-#define passivePositionParticleCloud_H
+#ifndef Foam_passivePositionParticleCloud_H
+#define Foam_passivePositionParticleCloud_H
 
 #include "Cloud.H"
 #include "passivePositionParticle.H"
@@ -53,23 +53,21 @@ class passivePositionParticleCloud
 :
     public Cloud<passivePositionParticle>
 {
-    // Private Member Functions
-
-        //- No copy construct
-        passivePositionParticleCloud
-        (
-            const passivePositionParticleCloud&
-        ) = delete;
-
-        //- No copy assignment
-        void operator=(const passivePositionParticleCloud&) = delete;
-
-
 public:
 
+    //- Type of parcel within the cloud
+    typedef passivePositionParticle parcelType;
+
+    //- No copy construct
+    passivePositionParticleCloud(const passivePositionParticleCloud&) = delete;
+
+    //- No copy assignment
+    void operator=(const passivePositionParticleCloud&) = delete;
+
+
     // Constructors
 
-        //- Construct given mesh
+        //- Read construct
         explicit passivePositionParticleCloud
         (
             const polyMesh& mesh,
@@ -77,13 +75,16 @@ public:
             bool readFields = true
         );
 
-        //- Construct from mesh, cloud name, and a list of particles
+        //- Construct without particles
         passivePositionParticleCloud
         (
             const polyMesh& mesh,
-            const word& cloudName,
-            const IDLList<passivePositionParticle>& particles
-        );
+            const Foam::zero,
+            const word& cloudName = cloud::defaultName
+        )
+        :
+            Cloud<passivePositionParticle>(mesh, Foam::zero{}, cloudName)
+        {}
 };
 
 

applications/utilities/parallelProcessing/redistributePar/unmappedPassivePositionParticleCloud.H

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2015 OpenFOAM Foundation
-    Copyright (C) 2019-2020 OpenCFD Ltd.
+    Copyright (C) 2019-2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -36,8 +36,8 @@ SourceFiles
 
 \*---------------------------------------------------------------------------*/
 
-#ifndef unmappedPassivePositionParticleCloud_H
-#define unmappedPassivePositionParticleCloud_H
+#ifndef Foam_unmappedPassivePositionParticleCloud_H
+#define Foam_unmappedPassivePositionParticleCloud_H
 
 #include "passivePositionParticleCloud.H"
 
@@ -54,12 +54,11 @@ class unmappedPassivePositionParticleCloud
 :
     public passivePositionParticleCloud
 {
-
 public:
 
     // Constructors
 
-        //- Construct given mesh
+        //- Read construct
         explicit unmappedPassivePositionParticleCloud
         (
             const polyMesh& mesh,
@@ -70,15 +69,15 @@ public:
             passivePositionParticleCloud(mesh, cloudName, readFields)
         {}
 
-        //- Construct from mesh, cloud name, and a list of particles
+        //- Construct without particles
         unmappedPassivePositionParticleCloud
         (
             const polyMesh& mesh,
-            const word& cloudName,
-            const IDLList<passivePositionParticle>& particles
+            const Foam::zero,
+            const word& cloudName = cloud::defaultName
         )
         :
-            passivePositionParticleCloud(mesh, cloudName, particles)
+            passivePositionParticleCloud(mesh, Foam::zero{}, cloudName)
         {}
 
 
@@ -89,7 +88,7 @@ public:
     // Member Functions
 
         //- Switch off remapping of cells of particles when
-        //  mesh topology changes
+        //- mesh topology changes
         virtual void autoMap(const mapPolyMesh&)
         {}