From d3e285b48b54c8b3b72768e93985145c4e14c05a Mon Sep 17 00:00:00 2001
From: Mark Olesen <Mark.Olesen@esi-group.com>
Date: Tue, 1 Nov 2022 13:57:10 +0100
Subject: [PATCH] ENH: add FixedList templated get<unsigned>() methods

- provides fast compile-time indexing for FixedList
  (invalid indices trigger a compiler error).

  This enables noexcept access, which can propagate into various
  other uses (eg, triFace, triPoints, ...)

ENH: add triangle edge vectors
---
 applications/test/FixedList/Test-FixedList.C  |   6 +
 .../test/boolVector/Test-boolVector.C         |   6 +-
 applications/test/faces/Test-faces.C          |  20 +++-
 applications/test/triTet/Test-triTet.C        |  12 +-
 .../containers/Lists/FixedList/FixedList.H    |  24 ++--
 .../containers/Lists/FixedList/FixedListI.H   |  18 +++
 src/OpenFOAM/meshes/meshShapes/edge/edge.H    |  35 +++---
 src/OpenFOAM/meshes/meshShapes/edge/edgeI.H   |   6 +-
 .../meshes/meshShapes/triFace/triFace.H       |  34 ++----
 .../meshes/meshShapes/triFace/triFaceI.H      | 108 +++++++-----------
 .../meshShapes/triFace/triFaceTemplates.C     |   8 +-
 .../meshes/primitiveShapes/line/line.H        |  19 +--
 .../meshes/primitiveShapes/line/lineI.H       |   6 +-
 .../primitiveShapes/tetrahedron/tetrahedron.H |  16 +--
 .../tetrahedron/tetrahedronI.H                |  32 +++---
 .../primitiveShapes/triangle/triangle.H       |  78 +++++++++----
 .../primitiveShapes/triangle/triangleI.H      |  61 ++++++++--
 .../primitives/Vector/bools/boolVector.H      |  20 ++--
 .../primitives/Vector/bools/boolVectorI.H     |  29 ++---
 src/OpenFOAM/primitives/tuples/Pair.H         |  18 +--
 src/OpenFOAM/primitives/tuples/PairI.H        |  16 +--
 src/OpenFOAM/primitives/tuples/Tuple2.H       |   8 +-
 22 files changed, 318 insertions(+), 262 deletions(-)

diff --git a/applications/test/FixedList/Test-FixedList.C b/applications/test/FixedList/Test-FixedList.C
index c8648ae05f..7e510d8c78 100644
--- a/applications/test/FixedList/Test-FixedList.C
+++ b/applications/test/FixedList/Test-FixedList.C
@@ -189,6 +189,12 @@ int main(int argc, char *argv[])
             << " hash:" << FixedList<label, 4>::hasher()(list1) << nl
             << " hash:" << Hash<FixedList<label, 4>>()(list1) << nl;
 
+        Info<< "get<0>: " << list1.get<0>() << nl;
+        Info<< "get<1>: " << list1.get<1>() << nl;
+        Info<< "get<2>: " << list1.get<2>() << nl;
+        Info<< "get<3>: " << list1.get<3>() << nl;
+// Will not compile:  Info<< "get<4>: " << list1.get<4>() << nl;
+
         label a[4] = {0, 1, 2, 3};
         FixedList<label, 4> list2(a);
 
diff --git a/applications/test/boolVector/Test-boolVector.C b/applications/test/boolVector/Test-boolVector.C
index 0c66d261f6..d345b55ddf 100644
--- a/applications/test/boolVector/Test-boolVector.C
+++ b/applications/test/boolVector/Test-boolVector.C
@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2020 OpenCFD Ltd.
+    Copyright (C) 2020-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -43,7 +43,7 @@ void print(const boolVector& v)
         << " any:" << Switch::name(v.any())
         << " all:" << Switch::name(v.all())
         << " none:" << Switch::name(v.none())
-        << " count:" << v.count() << nl;
+        << " on:" << v.count() << " off:" << v.count(false) << nl;
 }
 
 
@@ -68,7 +68,7 @@ int main(int argc, char *argv[])
     Info<< nl;
 
     {
-        boolVector vec{1, 0, 1};
+        boolVector vec(1, 0, 1);
         print(vec);
 
         vec.flip();
diff --git a/applications/test/faces/Test-faces.C b/applications/test/faces/Test-faces.C
index fab3d04ca1..9c8cfcea03 100644
--- a/applications/test/faces/Test-faces.C
+++ b/applications/test/faces/Test-faces.C
@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2016-2021 OpenCFD Ltd.
+    Copyright (C) 2016-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -33,6 +33,7 @@ Description
 
 #include "argList.H"
 #include "labelledTri.H"
+#include "edge.H"
 #include "faceList.H"
 #include "triFaceList.H"
 #include "pointList.H"
@@ -131,10 +132,25 @@ int main(int argc, char *argv[])
     testSign(f1, points2, testPoints);
     Info<< nl;
 
-    triFace t1({1, 2, 3});
+    // Initializer list
+    // triFace t1({1, 2, 3});
+
+    // Component-wise
+    {
+        edge e1(3, 2, 1);  // Inadvertent sort!!!
+        Info<< "edge:" << e1 << nl;
+    }
+
+    // Component-wise
+    triFace t1(1, 2, 3);
     Info<< "triFace:"; faceInfo(t1, points1); Info << nl;
     testSign(t1, points1, testPoints);
 
+    {
+        scalarField fld({0, 20, 20, 30});
+        Info<< "avg:" << t1.average(pointField::null(), fld) << nl;
+    }
+
     Info<< "triFace:"; faceInfo(t1, points2); Info << nl;
     testSign(t1, points2, testPoints);
     Info<< nl;
diff --git a/applications/test/triTet/Test-triTet.C b/applications/test/triTet/Test-triTet.C
index 5c850a4377..2f579d7a72 100644
--- a/applications/test/triTet/Test-triTet.C
+++ b/applications/test/triTet/Test-triTet.C
@@ -1,3 +1,4 @@
+#include "argList.H"
 #include "point.H"
 #include "triangle.H"
 #include "tetrahedron.H"
@@ -5,7 +6,7 @@
 
 using namespace Foam;
 
-int main()
+int main(int argc, char *argv[])
 {
     triangle<point, point> tri
     (
@@ -14,6 +15,12 @@ int main()
         vector(1, 1, 0)
     );
 
+    Info<< "triangle: " << tri << nl
+        << "  vecA: " << tri.vecA() << nl
+        << "  vecB: " << tri.vecB() << nl
+        << "  vecC: " << tri.vecC() << nl
+        << endl;
+
     Info<< "tri circumCentre = " << tri.circumCentre() << endl;
     Info<< "tri circumRadius = " << tri.circumRadius() << endl;
 
@@ -28,6 +35,8 @@ int main()
     Info<< "tet circumCentre = " << tet.circumCentre() << endl;
     Info<< "tet circumRadius = " << tet.circumRadius() << endl;
 
+    InfoErr<< "Enter four points: " << endl;
+
     vector a(Sin);
     vector b(Sin);
     vector c(Sin);
@@ -36,5 +45,6 @@ int main()
     Info<< "tet circumRadius = "
         << tetrahedron<point, point>(a, b, c, d).circumRadius() << endl;
 
+    Info<< "\nEnd\n";
     return 0;
 }
diff --git a/src/OpenFOAM/containers/Lists/FixedList/FixedList.H b/src/OpenFOAM/containers/Lists/FixedList/FixedList.H
index 0ff6b37164..2f2d7b2148 100644
--- a/src/OpenFOAM/containers/Lists/FixedList/FixedList.H
+++ b/src/OpenFOAM/containers/Lists/FixedList/FixedList.H
@@ -216,6 +216,22 @@ public:
         //  \note Only meaningful for contiguous data
         inline char* data_bytes() noexcept;
 
+        //- Number of contiguous bytes for the list data,
+        //  \note Only meaningful for contiguous data
+        inline static std::streamsize size_bytes() noexcept;
+
+        //- Number of contiguous bytes for the list data,
+        //- runtime FatalError if type is not contiguous
+        static std::streamsize byteSize();
+
+        //- Element access using compile-time indexing
+        template<unsigned Index>
+        inline T& get() noexcept;
+
+        //- Element access using compile-time indexing
+        template<unsigned Index>
+        inline const T& get() const noexcept;
+
         //- Access first element of the list, position [0]
         inline T& front() noexcept;
 
@@ -228,14 +244,6 @@ public:
         //- Access last element of the list, position [N-1]
         inline const T& back() const noexcept;
 
-        //- Number of contiguous bytes for the list data,
-        //  \note Only meaningful for contiguous data
-        inline static std::streamsize size_bytes() noexcept;
-
-        //- Number of contiguous bytes for the list data,
-        //- runtime FatalError if type is not contiguous
-        static std::streamsize byteSize();
-
         //- Return the forward circular index, i.e. next index
         //- which returns to the first at the end of the list
         inline label fcIndex(const label i) const;
diff --git a/src/OpenFOAM/containers/Lists/FixedList/FixedListI.H b/src/OpenFOAM/containers/Lists/FixedList/FixedListI.H
index d6e290d18e..f2617b3d4e 100644
--- a/src/OpenFOAM/containers/Lists/FixedList/FixedListI.H
+++ b/src/OpenFOAM/containers/Lists/FixedList/FixedListI.H
@@ -203,6 +203,24 @@ inline std::streamsize Foam::FixedList<T, N>::size_bytes() noexcept
 }
 
 
+template<class T, unsigned N>
+template<unsigned Index>
+inline T& Foam::FixedList<T, N>::get() noexcept
+{
+    static_assert(Index < N, "Address outside FixedList range");
+    return v_[Index];
+}
+
+
+template<class T, unsigned N>
+template<unsigned Index>
+inline const T& Foam::FixedList<T, N>::get() const noexcept
+{
+    static_assert(Index < N, "Address outside FixedList range");
+    return v_[Index];
+}
+
+
 template<class T, unsigned N>
 inline T& Foam::FixedList<T, N>::front() noexcept
 {
diff --git a/src/OpenFOAM/meshes/meshShapes/edge/edge.H b/src/OpenFOAM/meshes/meshShapes/edge/edge.H
index 60feefd475..b014650ce4 100644
--- a/src/OpenFOAM/meshes/meshShapes/edge/edge.H
+++ b/src/OpenFOAM/meshes/meshShapes/edge/edge.H
@@ -108,38 +108,28 @@ public:
     // Access
 
         //- The first vertex
-        label a() const { return labelPair::first(); }
+        label a() const noexcept { return labelPair::first(); }
 
         //- The second vertex
-        label b() const { return labelPair::second(); }
+        label b() const noexcept { return labelPair::second(); }
 
         //- The first vertex
-        label& a() { return labelPair::first(); }
+        label& a() noexcept { return labelPair::first(); }
 
         //- The second vertex
-        label& b() { return labelPair::second(); }
-
-
-        //- The first vertex label
-        using labelPair::first;
-
-        //- The second (last) vertex label
-        using labelPair::second;
-
-        //- The last (second) vertex label
-        using labelPair::last;
+        label& b() noexcept { return labelPair::second(); }
 
         //- The start (first) vertex label
-        label start() const { return labelPair::first(); }
+        label start() const noexcept { return labelPair::first(); }
 
         //- The end (last/second) vertex label
-        label end() const { return labelPair::second(); }
+        label end() const noexcept { return labelPair::second(); }
 
         //- The start (first) vertex label
-        label& start() { return labelPair::first(); }
+        label& start() noexcept { return labelPair::first(); }
 
-        //- The end (last/second) vertex label
-        label& end() { return labelPair::second(); }
+        //- The end (second/last) vertex label
+        label& end() noexcept { return labelPair::second(); }
 
 
         //- Return reverse edge as copy.
@@ -157,8 +147,11 @@ public:
         //  No special handling of negative point labels.
         inline label maxVertex() const;
 
-        //- Return true if the vertices are unique and non-negative.
-        inline bool valid() const;
+        //- True if the vertices are unique and non-negative.
+        inline bool good() const noexcept;
+
+        //- True if the vertices are unique and non-negative.
+        bool valid() const noexcept { return good(); }
 
         //- Return true if point label is found in edge.
         //  Always false for a negative label.
diff --git a/src/OpenFOAM/meshes/meshShapes/edge/edgeI.H b/src/OpenFOAM/meshes/meshShapes/edge/edgeI.H
index 448bd43346..c87dd54285 100644
--- a/src/OpenFOAM/meshes/meshShapes/edge/edgeI.H
+++ b/src/OpenFOAM/meshes/meshShapes/edge/edgeI.H
@@ -58,7 +58,7 @@ inline Foam::edge::edge(const labelPair& pair)
 
 inline Foam::edge::edge(const FixedList<label, 2>& list)
 :
-    labelPair(list.first(), list.last())
+    labelPair(list.get<0>(), list.get<1>())
 {}
 
 
@@ -80,7 +80,7 @@ inline Foam::edge::edge
     const FixedList<label, 2>& indices
 )
 :
-    labelPair(list[indices.first()], list[indices.last()])
+    labelPair(list[indices.get<0>()], list[indices.get<1>()])
 {}
 
 
@@ -104,7 +104,7 @@ inline Foam::label Foam::edge::maxVertex() const
 }
 
 
-inline bool Foam::edge::valid() const
+inline bool Foam::edge::good() const noexcept
 {
     return (first() != second() && first() >= 0 && second() >= 0);
 }
diff --git a/src/OpenFOAM/meshes/meshShapes/triFace/triFace.H b/src/OpenFOAM/meshes/meshShapes/triFace/triFace.H
index 94d3f1b128..9fbe3e4905 100644
--- a/src/OpenFOAM/meshes/meshShapes/triFace/triFace.H
+++ b/src/OpenFOAM/meshes/meshShapes/triFace/triFace.H
@@ -88,7 +88,7 @@ public:
         inline triFace();
 
         //- Construct from three point labels
-        inline triFace(const label p0, const label p1, const label p2);
+        inline triFace(const label p0, const label p1, const label p2) noexcept;
 
         //- Construct from an initializer list of three point labels
         inline explicit triFace(std::initializer_list<label> list);
@@ -112,41 +112,31 @@ public:
     // Access
 
         //- The first vertex
-        label a() const { return operator[](0); }
+        label a() const noexcept { return get<0>(); }
 
         //- The second vertex
-        label b() const { return operator[](1); }
+        label b() const noexcept { return get<1>(); }
 
         //- The third vertex
-        label c() const { return operator[](2); }
+        label c() const noexcept { return get<2>(); }
 
         //- The first vertex
-        label& a() { return operator[](0); }
+        label& a() noexcept { return get<0>(); }
 
         //- The second vertex
-        label& b() { return operator[](1); }
+        label& b() noexcept { return get<1>(); }
 
         //- The third vertex
-        label& c() { return operator[](2); }
-
-
-        //- The first vertex label
-        using FixedList<label, 3>::first;
-
-        //- The last (third) vertex label
-        using FixedList<label, 3>::last;
-
-        //- The second vertex label
-        label& second() { return operator[](1); }
-
-        //- The second vertex label
-        label second() const { return operator[](1); }
+        label& c() noexcept { return get<2>(); }
 
 
     // Queries
 
-        //- Return true if the vertices are unique and non-negative.
-        inline bool valid() const;
+        //- True if vertices are unique and non-negative.
+        inline bool good() const noexcept;
+
+        //- True if vertices are unique and non-negative.
+        bool valid() const noexcept { return good(); }
 
 
     // Other
diff --git a/src/OpenFOAM/meshes/meshShapes/triFace/triFaceI.H b/src/OpenFOAM/meshes/meshShapes/triFace/triFaceI.H
index 6a2d568609..fecdf95bee 100644
--- a/src/OpenFOAM/meshes/meshShapes/triFace/triFaceI.H
+++ b/src/OpenFOAM/meshes/meshShapes/triFace/triFaceI.H
@@ -67,11 +67,16 @@ inline Foam::triFace::triFace()
 {}
 
 
-inline Foam::triFace::triFace(const label p0, const label p1, const label p2)
+inline Foam::triFace::triFace
+(
+    const label p0,
+    const label p1,
+    const label p2
+) noexcept
 {
-    operator[](0) = p0;
-    operator[](1) = p1;
-    operator[](2) = p2;
+    a() = p0;
+    b() = p1;
+    c() = p2;
 }
 
 
@@ -105,13 +110,13 @@ inline Foam::triFace::triFace(Istream& is)
 
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
-inline bool Foam::triFace::valid() const
+inline bool Foam::triFace::good() const noexcept
 {
     return
     (
-        operator[](0) >= 0 && operator[](0) != operator[](1)
-     && operator[](1) >= 0 && operator[](1) != operator[](2)
-     && operator[](2) >= 0 && operator[](0) != operator[](2)
+        a() >= 0 && a() != b()
+     && b() >= 0 && b() != c()
+     && c() >= 0 && c() != a()
     );
 }
 
@@ -145,7 +150,7 @@ inline Foam::label Foam::triFace::collapse()
 
 inline void Foam::triFace::flip()
 {
-    std::swap(operator[](1), operator[](2));
+    std::swap(get<1>(), get<2>());
 }
 
 
@@ -153,9 +158,9 @@ inline Foam::pointField Foam::triFace::points(const UList<point>& pts) const
 {
     pointField p(3);
 
-    p[0] = pts[operator[](0)];
-    p[1] = pts[operator[](1)];
-    p[2] = pts[operator[](2)];
+    p[0] = pts[a()];
+    p[1] = pts[b()];
+    p[2] = pts[c()];
 
     return p;
 }
@@ -169,45 +174,25 @@ inline Foam::face Foam::triFace::triFaceFace() const
 
 inline Foam::triPointRef Foam::triFace::tri(const UList<point>& points) const
 {
-    return triPointRef
-    (
-        points[operator[](0)],
-        points[operator[](1)],
-        points[operator[](2)]
-    );
+    return triPointRef(points[a()], points[b()], points[c()]);
 }
 
 
 inline Foam::point Foam::triFace::centre(const UList<point>& points) const
 {
-    return triPointRef::centre
-    (
-        points[operator[](0)],
-        points[operator[](1)],
-        points[operator[](2)]
-    );
+    return triPointRef::centre(points[a()], points[b()], points[c()]);
 }
 
 
 inline Foam::vector Foam::triFace::areaNormal(const UList<point>& points) const
 {
-    return triPointRef::areaNormal
-    (
-        points[operator[](0)],
-        points[operator[](1)],
-        points[operator[](2)]
-    );
+    return triPointRef::areaNormal(points[a()], points[b()], points[c()]);
 }
 
 
 inline Foam::vector Foam::triFace::unitNormal(const UList<point>& points) const
 {
-    return triPointRef::unitNormal
-    (
-        points[operator[](0)],
-        points[operator[](1)],
-        points[operator[](2)]
-    );
+    return triPointRef::unitNormal(points[a()], points[b()], points[c()]);
 }
 
 
@@ -220,12 +205,7 @@ inline Foam::scalar Foam::triFace::mag(const UList<point>& points) const
 inline Foam::Pair<Foam::point>
 Foam::triFace::box(const UList<point>& points) const
 {
-    return triPointRef::box
-    (
-        points[operator[](0)],
-        points[operator[](1)],
-        points[operator[](2)]
-    );
+    return triPointRef::box(points[a()], points[b()], points[c()]);
 }
 
 
@@ -238,7 +218,7 @@ inline Foam::label Foam::triFace::nTriangles() const noexcept
 inline Foam::triFace Foam::triFace::reverseFace() const
 {
     // The starting points of the original and reverse face are identical.
-    return triFace(operator[](0), operator[](2), operator[](1));
+    return triFace(a(), c(), b());
 }
 
 
@@ -433,14 +413,14 @@ inline Foam::edgeList Foam::triFace::edges() const
 {
     edgeList theEdges(3);
 
-    theEdges[0].first()  = operator[](0);
-    theEdges[0].second() = operator[](1);
+    theEdges[0].first()  = a();
+    theEdges[0].second() = b();
 
-    theEdges[1].first()  = operator[](1);
-    theEdges[1].second() = operator[](2);
+    theEdges[1].first()  = b();
+    theEdges[1].second() = c();
 
-    theEdges[2].first()  = operator[](2);
-    theEdges[2].second() = operator[](0);
+    theEdges[2].first()  = c();
+    theEdges[2].second() = a();
 
     return theEdges;
 }
@@ -450,14 +430,14 @@ inline Foam::edgeList Foam::triFace::rcEdges() const
 {
     edgeList theEdges(3);
 
-    theEdges[0].first()  = operator[](0);
-    theEdges[0].second() = operator[](2);
+    theEdges[0].first()  = a();
+    theEdges[0].second() = c();
 
-    theEdges[1].first()  = operator[](2);
-    theEdges[1].second() = operator[](1);
+    theEdges[1].first()  = c();
+    theEdges[1].second() = b();
 
-    theEdges[2].first()  = operator[](1);
-    theEdges[2].second() = operator[](0);
+    theEdges[2].first()  = b();
+    theEdges[2].second() = a();
 
     return theEdges;
 }
@@ -465,20 +445,20 @@ inline Foam::edgeList Foam::triFace::rcEdges() const
 
 inline int Foam::triFace::edgeDirection(const Foam::edge& e) const
 {
-    if (e.first() == operator[](0))
+    if (e.first() == a())
     {
-        if (e.second() == operator[](1)) return 1;  // Forward
-        if (e.second() == operator[](2)) return -1; // Reverse
+        if (e.second() == b()) return 1;    // Forward
+        if (e.second() == c()) return -1;   // Reverse
     }
-    if (e.first() == operator[](1))
+    if (e.first() == b())
     {
-        if (e.second() == operator[](2)) return 1;  // Forward
-        if (e.second() == operator[](0)) return -1; // Reverse
+        if (e.second() == c()) return 1;    // Forward
+        if (e.second() == a()) return -1;   // Reverse
     }
-    if (e.first() == operator[](2))
+    if (e.first() == c())
     {
-        if (e.second() == operator[](0)) return 1;  // Forward
-        if (e.second() == operator[](1)) return -1; // Reverse
+        if (e.second() == a()) return 1;    // Forward
+        if (e.second() == b()) return -1;   // Reverse
     }
 
     return 0;  // Not found
diff --git a/src/OpenFOAM/meshes/meshShapes/triFace/triFaceTemplates.C b/src/OpenFOAM/meshes/meshShapes/triFace/triFaceTemplates.C
index ebef52c1e1..22a249586b 100644
--- a/src/OpenFOAM/meshes/meshShapes/triFace/triFaceTemplates.C
+++ b/src/OpenFOAM/meshes/meshShapes/triFace/triFaceTemplates.C
@@ -39,13 +39,7 @@ Type Foam::triFace::average
     // a triangle, do a direct calculation
     return
     (
-        (1.0/3.0)
-      *
-        (
-            fld[operator[](0)]
-          + fld[operator[](1)]
-          + fld[operator[](2)]
-        )
+        (1.0/3.0) * (fld[a()] + fld[b()] + fld[c()])
     );
 }
 
diff --git a/src/OpenFOAM/meshes/primitiveShapes/line/line.H b/src/OpenFOAM/meshes/primitiveShapes/line/line.H
index 9639264fd5..253f137201 100644
--- a/src/OpenFOAM/meshes/primitiveShapes/line/line.H
+++ b/src/OpenFOAM/meshes/primitiveShapes/line/line.H
@@ -105,16 +105,16 @@ public:
     // Member Functions
 
         //- The first vertex
-        const point& a() const { return Pair<point>::first(); }
+        const point& a() const noexcept { return Pair<point>::first(); }
 
         //- The second vertex
-        const point& b() const { return Pair<point>::second(); }
+        const point& b() const noexcept { return Pair<point>::second(); }
 
         //- The first vertex
-        point& a() { return Pair<point>::first(); }
+        point& a() noexcept { return Pair<point>::first(); }
 
         //- The second vertex
-        point& b() { return Pair<point>::second(); }
+        point& b() noexcept { return Pair<point>::second(); }
 
         //- Return as line reference
         inline linePointRef ln() const;
@@ -148,12 +148,13 @@ class line
 {
     // Private Data
 
-        //- First point
+        //- Reference to the first line point
         PointRef a_;
 
-        //- Second point
+        //- Reference to the second line point
         PointRef b_;
 
+
 public:
 
     // Constructors
@@ -189,15 +190,15 @@ public:
         //- The second (last) point
         PointRef second() const noexcept { return b_; }
 
-        //- The last (second) point
-        PointRef last() const noexcept { return b_; }
-
         //- The start (first) point
         PointRef start() const noexcept { return a_; }
 
         //- The end (second) point
         PointRef end() const noexcept { return b_; }
 
+        //- The last (second) point
+        PointRef last() const noexcept { return b_; }
+
 
     // Line properties (static calculations)
 
diff --git a/src/OpenFOAM/meshes/primitiveShapes/line/lineI.H b/src/OpenFOAM/meshes/primitiveShapes/line/lineI.H
index d4bb63aada..5707547858 100644
--- a/src/OpenFOAM/meshes/primitiveShapes/line/lineI.H
+++ b/src/OpenFOAM/meshes/primitiveShapes/line/lineI.H
@@ -43,7 +43,7 @@ inline Foam::linePoints::linePoints
     const FixedList<label, 2>& indices
 )
 :
-    Pair<point>(points[indices.first()], points[indices.last()])
+    Pair<point>(points[indices.get<0>()], points[indices.get<1>()])
 {}
 
 
@@ -66,8 +66,8 @@ inline Foam::line<Point, PointRef>::line
     const FixedList<label, 2>& indices
 )
 :
-    a_(points[indices.first()]),
-    b_(points[indices.last()])
+    a_(points[indices.template get<0>()]),
+    b_(points[indices.template get<1>()])
 {}
 
 
diff --git a/src/OpenFOAM/meshes/primitiveShapes/tetrahedron/tetrahedron.H b/src/OpenFOAM/meshes/primitiveShapes/tetrahedron/tetrahedron.H
index f0f10e25db..3a31dd5d21 100644
--- a/src/OpenFOAM/meshes/primitiveShapes/tetrahedron/tetrahedron.H
+++ b/src/OpenFOAM/meshes/primitiveShapes/tetrahedron/tetrahedron.H
@@ -126,28 +126,28 @@ public:
     // Member Functions
 
         //- The first vertex
-        const point& a() const { return operator[](0); }
+        const point& a() const noexcept { return get<0>(); }
 
         //- The second vertex
-        const point& b() const { return operator[](1); }
+        const point& b() const noexcept { return get<1>(); }
 
         //- The third vertex
-        const point& c() const { return operator[](2); }
+        const point& c() const noexcept { return get<2>(); }
 
         //- The fourth vertex
-        const point& d() const { return operator[](3); }
+        const point& d() const noexcept { return get<3>(); }
 
         //- The first vertex
-        point& a() { return operator[](0); }
+        point& a() noexcept { return get<0>(); }
 
         //- The second vertex
-        point& b() { return operator[](1); }
+        point& b() noexcept { return get<1>(); }
 
         //- The third vertex
-        point& c() { return operator[](2); }
+        point& c() noexcept { return get<2>(); }
 
         //- The fourth vertex
-        point& d() { return operator[](3); }
+        point& d() noexcept { return get<3>(); }
 
         //- Return as tetrahedron reference
         inline tetPointRef tet() const;
diff --git a/src/OpenFOAM/meshes/primitiveShapes/tetrahedron/tetrahedronI.H b/src/OpenFOAM/meshes/primitiveShapes/tetrahedron/tetrahedronI.H
index b3cdd7ecb6..951dc07193 100644
--- a/src/OpenFOAM/meshes/primitiveShapes/tetrahedron/tetrahedronI.H
+++ b/src/OpenFOAM/meshes/primitiveShapes/tetrahedron/tetrahedronI.H
@@ -40,19 +40,19 @@ inline Foam::tetPoints::tetPoints
     const point& p3
 )
 {
-    operator[](0) = p0;
-    operator[](1) = p1;
-    operator[](2) = p2;
-    operator[](3) = p3;
+    a() = p0;
+    b() = p1;
+    c() = p2;
+    d() = p3;
 }
 
 
 inline Foam::tetPoints::tetPoints(const tetPointRef& pts)
 {
-    operator[](0) = pts.a();
-    operator[](1) = pts.b();
-    operator[](2) = pts.c();
-    operator[](3) = pts.d();
+    a() = pts.a();
+    b() = pts.b();
+    c() = pts.c();
+    d() = pts.d();
 }
 
 
@@ -94,10 +94,10 @@ inline Foam::tetrahedron<Point, PointRef>::tetrahedron
     const FixedList<Point, 4>& pts
 )
 :
-    a_(pts[0]),
-    b_(pts[1]),
-    c_(pts[2]),
-    d_(pts[3])
+    a_(pts.template get<0>()),
+    b_(pts.template get<1>()),
+    c_(pts.template get<2>()),
+    d_(pts.template get<3>())
 {}
 
 
@@ -108,10 +108,10 @@ inline Foam::tetrahedron<Point, PointRef>::tetrahedron
     const FixedList<label, 4>& indices
 )
 :
-    a_(points[indices[0]]),
-    b_(points[indices[1]]),
-    c_(points[indices[2]]),
-    d_(points[indices[3]])
+    a_(points[indices.template get<0>()]),
+    b_(points[indices.template get<1>()]),
+    c_(points[indices.template get<2>()]),
+    d_(points[indices.template get<3>()])
 {}
 
 
diff --git a/src/OpenFOAM/meshes/primitiveShapes/triangle/triangle.H b/src/OpenFOAM/meshes/primitiveShapes/triangle/triangle.H
index f571c896e1..88693507ab 100644
--- a/src/OpenFOAM/meshes/primitiveShapes/triangle/triangle.H
+++ b/src/OpenFOAM/meshes/primitiveShapes/triangle/triangle.H
@@ -114,22 +114,22 @@ public:
     // Member Functions
 
         //- The first vertex
-        const point& a() const { return operator[](0); }
+        const point& a() const noexcept { return get<0>(); }
 
         //- The second vertex
-        const point& b() const { return operator[](1); }
+        const point& b() const noexcept { return get<1>(); }
 
         //- The third vertex
-        const point& c() const { return operator[](2); }
+        const point& c() const noexcept { return get<2>(); }
 
         //- The first vertex
-        point& a() { return operator[](0); }
+        point& a() noexcept { return get<0>(); }
 
         //- The second vertex
-        point& b() { return operator[](1); }
+        point& b() noexcept { return get<1>(); }
 
         //- The third vertex
-        point& c() { return operator[](2); }
+        point& c() noexcept { return get<2>(); }
 
         //- Flip triangle orientation by swapping second and third vertices
         inline void flip();
@@ -154,6 +154,15 @@ public:
 
         //- The enclosing (bounding) box for the triangle
         inline Pair<point> box() const;
+
+        //- Edge vector opposite point a(): from b() to c()
+        inline vector vecA() const;
+
+        //- Edge vector opposite point b(): from c() to a()
+        inline vector vecB() const;
+
+        //- Edge vector opposite point c(): from a() to b()
+        inline vector vecC() const;
 };
 
 
@@ -224,7 +233,14 @@ private:
 
     // Private Data
 
-        PointRef a_, b_, c_;
+        //- Reference to the first triangle point
+        PointRef a_;
+
+        //- Reference to the second triangle point
+        PointRef b_;
+
+        //- Reference to the third triangle point
+        PointRef c_;
 
 
    // Private Member Functions
@@ -322,30 +338,42 @@ public:
         );
 
 
-        // Properties
+    // Properties
 
-            //- Return centre (centroid)
-            inline Point centre() const;
+        //- Return centre (centroid)
+        inline Point centre() const;
 
-            //- The area normal - with magnitude equal to area of triangle
-            inline vector areaNormal() const;
+        //- The area normal - with magnitude equal to area of triangle
+        inline vector areaNormal() const;
 
-            //- Return unit normal
-            inline vector unitNormal() const;
+        //- Return unit normal
+        inline vector unitNormal() const;
 
-            //- Legacy name for areaNormal().
-            //  \deprecated(2018-06) Deprecated for new use
-            FOAM_DEPRECATED_FOR(2018-12, "areaNormal() or unitNormal()")
-            vector normal() const
-            {
-                return areaNormal();
-            }
+        //- Legacy name for areaNormal().
+        //  \deprecated(2018-06) Deprecated for new use
+        FOAM_DEPRECATED_FOR(2018-12, "areaNormal() or unitNormal()")
+        vector normal() const
+        {
+            return areaNormal();
+        }
 
-            //- The magnitude of the triangle area
-            inline scalar mag() const;
+        //- The magnitude of the triangle area
+        inline scalar mag() const;
 
-            //- The enclosing (bounding) box for the triangle
-            inline Pair<Point> box() const;
+        //- The enclosing (bounding) box for the triangle
+        inline Pair<Point> box() const;
+
+        //- Edge vector opposite point a(): from b() to c()
+        inline Point vecA() const;
+
+        //- Edge vector opposite point b(): from c() to a()
+        inline Point vecB() const;
+
+        //- Edge vector opposite point c(): from a() to b()
+        inline Point vecC() const;
+
+
+    // Properties
 
             //- Return circum-centre
             inline Point circumCentre() const;
diff --git a/src/OpenFOAM/meshes/primitiveShapes/triangle/triangleI.H b/src/OpenFOAM/meshes/primitiveShapes/triangle/triangleI.H
index 68cba504d9..64c0134f0a 100644
--- a/src/OpenFOAM/meshes/primitiveShapes/triangle/triangleI.H
+++ b/src/OpenFOAM/meshes/primitiveShapes/triangle/triangleI.H
@@ -39,17 +39,17 @@ inline Foam::triPoints::triPoints
     const point& p2
 )
 {
-    operator[](0) = p0;
-    operator[](1) = p1;
-    operator[](2) = p2;
+    a() = p0;
+    b() = p1;
+    c() = p2;
 }
 
 
 inline Foam::triPoints::triPoints(const triPointRef& pts)
 {
-    operator[](0) = pts.a();
-    operator[](1) = pts.b();
-    operator[](2) = pts.c();
+    a() = pts.a();
+    b() = pts.b();
+    c() = pts.c();
 }
 
 
@@ -89,9 +89,9 @@ inline Foam::triangle<Point, PointRef>::triangle
     const FixedList<Point, 3>& pts
 )
 :
-    a_(pts[0]),
-    b_(pts[1]),
-    c_(pts[2])
+    a_(pts.template get<0>()),
+    b_(pts.template get<1>()),
+    c_(pts.template get<2>())
 {}
 
 
@@ -102,9 +102,9 @@ inline Foam::triangle<Point, PointRef>::triangle
     const FixedList<label, 3>& indices
 )
 :
-    a_(points[indices[0]]),
-    b_(points[indices[1]]),
-    c_(points[indices[2]])
+    a_(points[indices.template get<0>()]),
+    b_(points[indices.template get<1>()]),
+    c_(points[indices.template get<2>()])
 {}
 
 
@@ -223,6 +223,43 @@ inline Foam::Pair<Foam::point> Foam::triPoints::box() const
 }
 
 
+template<class Point, class PointRef>
+inline Point Foam::triangle<Point, PointRef>::vecA() const
+{
+    return Point(c_ - b_);
+}
+
+template<class Point, class PointRef>
+inline Point Foam::triangle<Point, PointRef>::vecB() const
+{
+    return Point(a_ - c_);
+}
+
+template<class Point, class PointRef>
+inline Point Foam::triangle<Point, PointRef>::vecC() const
+{
+    return Point(b_ - a_);
+}
+
+
+inline Foam::vector Foam::triPoints::vecA() const
+{
+    return vector(c() - b());
+}
+
+
+inline Foam::vector Foam::triPoints::vecB() const
+{
+    return vector(a() - c());
+}
+
+
+inline Foam::vector Foam::triPoints::vecC() const
+{
+    return vector(b() - a());
+}
+
+
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
 inline Foam::triPointRef Foam::triPoints::tri() const
diff --git a/src/OpenFOAM/primitives/Vector/bools/boolVector.H b/src/OpenFOAM/primitives/Vector/bools/boolVector.H
index 237c17df42..baa2e81bb5 100644
--- a/src/OpenFOAM/primitives/Vector/bools/boolVector.H
+++ b/src/OpenFOAM/primitives/Vector/bools/boolVector.H
@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2020 OpenCFD Ltd.
+    Copyright (C) 2020-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -112,17 +112,17 @@ public:
         //- True if all components are set
         //
         //  \note Method name compatibility with bitSet
-        inline bool all() const;
+        inline bool all() const noexcept;
 
         //- True if any components are set
         //
         //  \note Method name compatibility with bitSet
-        inline bool any() const;
+        inline bool any() const noexcept;
 
         //- True if no components are set
         //
         //  \note Method name compatibility with bitSet
-        inline bool none() const;
+        inline bool none() const noexcept;
 
         //- Count number of items set.
         //  \param on can be set to false to count the number of unset bits
@@ -135,22 +135,22 @@ public:
     // Component Access
 
         //- The x component
-        bool x() const { return operator[](boolVector::X); }
+        bool x() const noexcept { return get<0>(); }
 
         //- The y component
-        bool y() const { return operator[](boolVector::Y); }
+        bool y() const noexcept { return get<1>(); }
 
         //- The z component
-        bool z() const { return operator[](boolVector::Z); }
+        bool z() const noexcept { return get<2>(); }
 
         //- The x component
-        bool& x() { return operator[](boolVector::X); }
+        bool& x() noexcept { return get<0>(); }
 
         //- The y component
-        bool& y() { return operator[](boolVector::Y); }
+        bool& y() noexcept { return get<1>(); }
 
         //- The z component
-        bool& z() { return operator[](boolVector::Z); }
+        bool& z() noexcept { return get<2>(); }
 
 
     // Edit
diff --git a/src/OpenFOAM/primitives/Vector/bools/boolVectorI.H b/src/OpenFOAM/primitives/Vector/bools/boolVectorI.H
index 0d7622c957..00ed8b4af8 100644
--- a/src/OpenFOAM/primitives/Vector/bools/boolVectorI.H
+++ b/src/OpenFOAM/primitives/Vector/bools/boolVectorI.H
@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2020 OpenCFD Ltd.
+    Copyright (C) 2020-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -45,8 +45,6 @@ inline Foam::boolVector::boolVector
     const bool vy,
     const bool vz
 )
-:
-    FixedList<bool, 3>()
 {
     x() = vx;
     y() = vy;
@@ -62,27 +60,19 @@ inline Foam::boolVector::boolVector(Istream& is)
 
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
-inline bool Foam::boolVector::all() const
+inline bool Foam::boolVector::all() const noexcept
 {
-    for (const bool val : *this)
-    {
-        if (!val) return false;
-    }
-    return true;
+    return (x() && y() && z());
 }
 
 
-inline bool Foam::boolVector::any() const
+inline bool Foam::boolVector::any() const noexcept
 {
-    for (const bool val : *this)
-    {
-        if (val) return true;
-    }
-    return false;
+    return (x() || y() || z());
 }
 
 
-inline bool Foam::boolVector::none() const
+inline bool Foam::boolVector::none() const noexcept
 {
     return !any();
 }
@@ -109,10 +99,9 @@ inline unsigned int Foam::boolVector::count(const bool on) const
 
 inline void Foam::boolVector::flip()
 {
-    for (bool& val : *this)
-    {
-        val = !val;
-    }
+    x() = !x();
+    y() = !y();
+    z() = !z();
 }
 
 
diff --git a/src/OpenFOAM/primitives/tuples/Pair.H b/src/OpenFOAM/primitives/tuples/Pair.H
index 3a6292064a..eaaf3a93ef 100644
--- a/src/OpenFOAM/primitives/tuples/Pair.H
+++ b/src/OpenFOAM/primitives/tuples/Pair.H
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2017-2021 OpenCFD Ltd.
+    Copyright (C) 2017-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -113,17 +113,17 @@ public:
 
     // Access
 
-        //- Return first element
-        using FixedList<T, 2>::first;
+        //- Access the first element
+        const T& first() const noexcept { return this->template get<0>(); }
 
-        //- Return last element
-        using FixedList<T, 2>::last;
+        //- Access the first element
+        T& first() noexcept { return this->template get<0>(); }
 
-        //- Return second element, which is also the last element
-        inline const T& second() const noexcept;
+        //- Access the second element
+        const T& second() const noexcept { return this->template get<1>(); }
 
-        //- Return second element, which is also the last element
-        inline T& second() noexcept;
+        //- Access the second element
+        T& second() noexcept { return this->template get<1>(); }
 
         //- Return other element
         inline const T& other(const T& a) const;
diff --git a/src/OpenFOAM/primitives/tuples/PairI.H b/src/OpenFOAM/primitives/tuples/PairI.H
index f8b49c84a5..841bf8c349 100644
--- a/src/OpenFOAM/primitives/tuples/PairI.H
+++ b/src/OpenFOAM/primitives/tuples/PairI.H
@@ -103,7 +103,7 @@ inline Foam::Pair<T>::Pair(const T& f, const T& s, const bool doSort)
 template<class T>
 inline Foam::Pair<T>::Pair(const FixedList<T, 2>& list, const bool doSort)
 :
-    Pair<T>(list.first(), list.last(), doSort)
+    Pair<T>(list.template get<0>(), list.template get<1>(), doSort)
 {}
 
 
@@ -116,20 +116,6 @@ inline Foam::Pair<T>::Pair(Istream& is)
 
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
-template<class T>
-inline const T& Foam::Pair<T>::second() const noexcept
-{
-    return last();
-}
-
-
-template<class T>
-inline T& Foam::Pair<T>::second() noexcept
-{
-    return last();
-}
-
-
 template<class T>
 inline const T& Foam::Pair<T>::other(const T& val) const
 {
diff --git a/src/OpenFOAM/primitives/tuples/Tuple2.H b/src/OpenFOAM/primitives/tuples/Tuple2.H
index bd63390228..6c6fe3d1ee 100644
--- a/src/OpenFOAM/primitives/tuples/Tuple2.H
+++ b/src/OpenFOAM/primitives/tuples/Tuple2.H
@@ -117,16 +117,16 @@ public:
 
     // Member Functions
 
-        //- Return first
+        //- Access the first element
         const T1& first() const noexcept { return f_; }
 
-        //- Return first
+        //- Access the first element
         T1& first() noexcept { return f_; }
 
-        //- Return second
+        //- Access the second element
         const T2& second() const noexcept { return s_; }
 
-        //- Return second
+        //- Access the second element
         T2& second() noexcept { return s_; }
 };