ENH: refine PtrList emplace method, add emplace for autoPtr/refPtr...

* resize_null() methods for PtrList variants
  - for cases where an existing PtrList needs a specific size and
    but not retain any existing entries.

    Eg,
        ptrs.resize_null(100);

    vs.   ptrs.free();     ptr.resize(100);
    or    ptr.resize(100); ptrs.free();

* remove stored pointer before emplacing PtrList elements
  - may reduce memory peaks

* STYLE: static_cast of (nullptr) instead of reinterpret_cast of (0)

* COMP: implement emplace_set() for PtrDynList
  - previously missing, which meant it would have leaked through to the
    underlying PtrList definition

* emplace methods for autoPtr, refPtr, tmp
  - applies reset() with forwarding arguments.
    For example,

        tmp<GeoField> tfld = ...;

    later...

        tfld.emplace(io, mesh);

    vs.
        tfld.reset(new GeoField(io, mesh));
    or
        tfld.reset(tmp<GeoField>::New(io, mesh));

    The emplace() obviously has reduced typing, but also allows the
    existing stored pointer to be deleted *before* creating its
    replacement (reduces memory peaks).

applications/test/PtrList/Test-PtrList.C

@@ -47,43 +47,39 @@ class Scalar
 
 public:
 
-    Scalar()
+    static bool verbose;
+
+    constexpr Scalar() noexcept
     :
         data_(0)
     {}
 
-    Scalar(scalar val)
+    Scalar(scalar val) noexcept
     :
         data_(val)
     {}
 
     ~Scalar()
     {
-        Info<< "delete Scalar: " << data_ << endl;
+        if (verbose) Info<< "delete Scalar: " << data_ << endl;
     }
 
-    const scalar& value() const
-    {
-        return data_;
-    }
-
-    scalar& value()
-    {
-        return data_;
-    }
+    scalar value() const noexcept { return data_; }
+    scalar& value() noexcept { return data_; }
 
     autoPtr<Scalar> clone() const
     {
         return autoPtr<Scalar>::New(data_);
     }
 
-    friend Ostream& operator<<(Ostream& os, const Scalar& val)
+    friend Ostream& operator<<(Ostream& os, const Scalar& item)
     {
-        os  << val.data_;
+        os  << item.value();
         return os;
     }
 };
 
+bool Scalar::verbose = true;
 
 
 // As per
@@ -268,6 +264,22 @@ Ostream& report
 
 int main(int argc, char *argv[])
 {
+    #if 1
+    {
+        DLPtrList<Scalar> llist1;
+        Info<< "emplace_front: " << llist1.emplace_front(100) << nl;
+        Info<< "emplace_front: " << llist1.emplace_front(200) << nl;
+        Info<< "emplace_front: " << llist1.emplace_front(300) << nl;
+        Info<< "emplace_back:  " << llist1.emplace_back(500)  << nl;
+
+        Info<< "DLPtrList: " << llist1 << endl;
+
+        Scalar::verbose = false;
+        llist1.clear();
+        Scalar::verbose = true;
+    }
+    #endif
+
     #if 0
     {
         DLPtrList<Scalar> llist1;
@@ -349,6 +361,16 @@ int main(int argc, char *argv[])
         list2.emplace(i, (10 + 1.3*i));
     }
 
+    #if 0
+    list2.release(5);
+    list2.release(10);
+
+    forAll(list2, i)
+    {
+        list2.try_emplace(i, (50 + 1.3*i));
+    }
+    #endif
+
     PtrList<Scalar> listApp;
     for (label i = 0; i < 5; ++i)
     {
@@ -639,7 +661,7 @@ int main(int argc, char *argv[])
         dynPlanes.set(6, new plane(vector(2,2,1), vector::one));
         dynPlanes.set(10, new plane(vector(4,5,6), vector::one));
 
-        Info<< "emplaced :"
+        Info<< "emplaced[12]: "
             << dynPlanes.emplace(12, vector(3,2,1), vector::one) << endl;
 
         dynPlanes.emplace_back(Zero, vector::one);

applications/test/autoPtr/Test-autoPtr.C

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2018-2022 OpenCFD Ltd.
+    Copyright (C) 2018-2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -84,6 +84,20 @@ struct DerivedList : public List<T>
 };
 
 
+template<class T>
+void printInfo(const autoPtr<T>& item, const bool verbose = false)
+{
+    Info<< "autoPtr good:" << Switch::name(item.good())
+        << " addr: " << Foam::name(item.get());
+
+    if (verbose && item)
+    {
+        Info<< " content: " << item();
+    }
+    Info<< nl;
+}
+
+
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 //  Main program:
 
@@ -112,6 +126,17 @@ int main(int argc, char *argv[])
 
         Info<<"move unique to autoPtr: " << *list3 << nl;
         Info<<"old is " << Switch(bool(list2)) << nl;
+
+        Info<< "before emplace: ";
+        printInfo(list, true);
+
+        list.emplace(4, label(-2));
+        Info<< "after emplace: ";
+        printInfo(list, true);
+
+        list.emplace(2, label(-4));
+        Info<< "after emplace: ";
+        printInfo(list, true);
     }
 
     // Confirm that forwarding with move construct actually works as expected

applications/test/refPtr/Test-refPtr.C

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2020-2022 OpenCFD Ltd.
+    Copyright (C) 2020-2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM, distributed under GPL-3.0-or-later.
@@ -105,12 +105,21 @@ int main()
         Info<< nl << "Construct from reference" << nl;
 
         scalarField f2(10, Foam::sqrt(2.0));
-        printInfo(refPtr<scalarField>(f2), true);
+        refPtr<scalarField> tfld2(f2);
+        printInfo(tfld2, true);
+
+        Info<< nl << "emplaced:"<< nl;
+        tfld2.emplace(25, scalar(1));
+        printInfo(tfld2, true);
     }
 
     {
         Info<< nl << "Construct from New (is_pointer)" << nl;
-        auto tfld1 = refPtr<scalarField>::New(10, scalar(1));
+        auto tfld1 = refPtr<scalarField>::New(10, scalar(-1));
+        printInfo(tfld1, true);
+
+        Info<< nl << "emplaced:"<< nl;
+        tfld1.emplace(15, scalar(1));
         printInfo(tfld1, true);
 
         Info<< nl << "Dereferenced: " << *tfld1 << nl;

applications/test/tmp/Test-tmp.C

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2018-2021 OpenCFD Ltd.
+    Copyright (C) 2018-2023 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM, distributed under GPL-3.0-or-later.
@@ -78,7 +78,10 @@ int main()
     }
 
     {
-        auto tfld1 = tmp<scalarField>::New(20, Zero);
+        auto tfld1 = tmp<scalarField>::New(10, Zero);
+        printInfo(tfld1, true);
+
+        tfld1.emplace(20, Zero);
         printInfo(tfld1, true);
 
         // Hold on to the old content for a bit