ENH: return const pointer instead of bool from PtrList::set(label)

- can still test as a bool or use to 'peek' at the content.

src/OpenFOAM/containers/PtrLists/PtrList/PtrList.H

@@ -3,7 +3,7 @@
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
     \\  /    A nd           | Copyright (C) 2011-2016 OpenFOAM Foundation
-     \\/     M anipulation  | Copyright (C) 2018 OpenCFD Ltd.
+     \\/     M anipulation  | Copyright (C) 2018-2019 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -150,21 +150,22 @@ public:
         //- Transfer into this list and annul the argument list
         inline void transfer(PtrList<T>& list);
 
-        //- Return true if element is set (ie, not a nullptr)
-        inline bool set(const label i) const;
+        //- Return const pointer to element (if set) or nullptr.
+        //  The return value can be tested as a bool.
+        inline const T* set(const label i) const;
 
         //- Set element to given pointer and return old element (can be null)
         //  No-op if the new pointer value is identical to the current content.
-        inline autoPtr<T> set(label i, T* ptr);
+        inline autoPtr<T> set(const label i, T* ptr);
 
         //- Set element to given autoPtr and return old element
-        inline autoPtr<T> set(label i, autoPtr<T>& aptr);
+        inline autoPtr<T> set(const label i, autoPtr<T>& aptr);
 
         //- Set element to given autoPtr and return old element
-        inline autoPtr<T> set(label i, autoPtr<T>&& aptr);
+        inline autoPtr<T> set(const label i, autoPtr<T>&& aptr);
 
         //- Set element to given tmp and return old element
-        inline autoPtr<T> set(label i, const tmp<T>& tptr);
+        inline autoPtr<T> set(const label i, const tmp<T>& tptr);
 
 
     // Member Operators

src/OpenFOAM/containers/PtrLists/PtrList/PtrListI.H

@@ -3,7 +3,7 @@
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
     \\  /    A nd           | Copyright (C) 2011-2016 OpenFOAM Foundation
-     \\/     M anipulation  | Copyright (C) 2018 OpenCFD Ltd.
+     \\/     M anipulation  | Copyright (C) 2018-2019 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -123,35 +123,35 @@ inline void Foam::PtrList<T>::append(const tmp<T>& tptr)
 
 
 template<class T>
-inline bool Foam::PtrList<T>::set(const label i) const
+inline const T* Foam::PtrList<T>::set(const label i) const
 {
     return UPtrList<T>::set(i);
 }
 
 
 template<class T>
-inline Foam::autoPtr<T> Foam::PtrList<T>::set(label i, T* ptr)
+inline Foam::autoPtr<T> Foam::PtrList<T>::set(const label i, T* ptr)
 {
     return autoPtr<T>(UPtrList<T>::set(i, ptr));
 }
 
 
 template<class T>
-inline Foam::autoPtr<T> Foam::PtrList<T>::set(label i, autoPtr<T>& aptr)
+inline Foam::autoPtr<T> Foam::PtrList<T>::set(const label i, autoPtr<T>& aptr)
 {
     return set(i, aptr.release());
 }
 
 
 template<class T>
-inline Foam::autoPtr<T> Foam::PtrList<T>::set(label i, autoPtr<T>&& aptr)
+inline Foam::autoPtr<T> Foam::PtrList<T>::set(const label i, autoPtr<T>&& aptr)
 {
     return set(i, aptr.release());
 }
 
 
 template<class T>
-inline Foam::autoPtr<T> Foam::PtrList<T>::set(label i, const tmp<T>& tptr)
+inline Foam::autoPtr<T> Foam::PtrList<T>::set(const label i, const tmp<T>& tptr)
 {
     return set(i, tptr.ptr());
 }

src/OpenFOAM/containers/PtrLists/UPtrList/UPtrList.H

@@ -3,7 +3,7 @@
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
     \\  /    A nd           | Copyright (C) 2011-2016 OpenFOAM Foundation
-     \\/     M anipulation  | Copyright (C) 2018 OpenCFD Ltd.
+     \\/     M anipulation  | Copyright (C) 2018-2019 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -177,8 +177,9 @@ public:
         //- Transfer contents into this list and annul the argument
         inline void transfer(UPtrList<T>& list);
 
-        //- Return true if element is set (not a nullptr)
-        inline bool set(const label i) const;
+        //- Return const pointer to element (if set) or nullptr.
+        //  The return value can be tested as a bool.
+        inline const T* set(const label i) const;
 
         //- Set element to specified pointer and return the old list element,
         //- which can be a nullptr.

src/OpenFOAM/containers/PtrLists/UPtrList/UPtrListI.H

@@ -3,7 +3,7 @@
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
     \\  /    A nd           | Copyright (C) 2011-2016 OpenFOAM Foundation
-     \\/     M anipulation  | Copyright (C) 2018 OpenCFD Ltd.
+     \\/     M anipulation  | Copyright (C) 2018-2019 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -170,9 +170,9 @@ inline void Foam::UPtrList<T>::append(T* ptr)
 
 
 template<class T>
-inline bool Foam::UPtrList<T>::set(const label i) const
+inline const T* Foam::UPtrList<T>::set(const label i) const
 {
-    return ptrs_[i] != nullptr;
+    return ptrs_[i];
 }
 
 
@@ -199,7 +199,7 @@ inline const T& Foam::UPtrList<T>::operator[](const label i) const
     if (!ptr)
     {
         FatalErrorInFunction
-            << "cannot dereference nullptr at index " << i
+            << "Cannot dereference nullptr at index " << i
             << " in range [0," << size() << ")"
             << abort(FatalError);
     }
@@ -216,7 +216,7 @@ inline T& Foam::UPtrList<T>::operator[](const label i)
     if (!ptr)
     {
         FatalErrorInFunction
-            << "cannot dereference nullptr at index " << i
+            << "Cannot dereference nullptr at index " << i
             << " in range [0," << size() << ")"
             << abort(FatalError);
     }