diff --git a/applications/test/HashSet/Test-hashSet.C b/applications/test/HashSet/Test-hashSet.C
index 7ead0c4285..425320bc39 100644
--- a/applications/test/HashSet/Test-hashSet.C
+++ b/applications/test/HashSet/Test-hashSet.C
@@ -56,7 +56,7 @@ int main(int argc, char *argv[])
 
     setA = { "kjhk", "kjhk2", "abced" };
 
-    HashTable<label, word> tableA
+    HashTable<label> tableA
     {
         { "value1", 1 },
         { "value2", 2 },
diff --git a/applications/utilities/mesh/conversion/ideasUnvToFoam/ideasUnvToFoam.C b/applications/utilities/mesh/conversion/ideasUnvToFoam/ideasUnvToFoam.C
index ca7172a715..762bdf92d5 100644
--- a/applications/utilities/mesh/conversion/ideasUnvToFoam/ideasUnvToFoam.C
+++ b/applications/utilities/mesh/conversion/ideasUnvToFoam/ideasUnvToFoam.C
@@ -853,7 +853,7 @@ int main(int argc, char *argv[])
 
     labelList own(boundaryFaces.size(), -1);
     labelList nei(boundaryFaces.size(), -1);
-    HashTable<label, label> faceToCell[2];
+    Map<label> faceToCell[2];
 
     {
         HashTable<label, face, Hash<face>> faceToFaceID(boundaryFaces.size());
diff --git a/applications/utilities/mesh/generation/foamyMesh/conformalVoronoiMesh/PrintTable/PrintTable.C b/applications/utilities/mesh/generation/foamyMesh/conformalVoronoiMesh/PrintTable/PrintTable.C
index abedb2c905..7be15695bc 100644
--- a/applications/utilities/mesh/generation/foamyMesh/conformalVoronoiMesh/PrintTable/PrintTable.C
+++ b/applications/utilities/mesh/generation/foamyMesh/conformalVoronoiMesh/PrintTable/PrintTable.C
@@ -54,13 +54,6 @@ Foam::PrintTable<KeyType, DataType>::PrintTable
 {}
 
 
-// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
-
-template<class KeyType, class DataType>
-Foam::PrintTable<KeyType, DataType>::~PrintTable()
-{}
-
-
 // * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
 
 template<class KeyType, class DataType>
@@ -71,7 +64,7 @@ void Foam::PrintTable<KeyType, DataType>::print
     const bool printAverage
 ) const
 {
-    HashTable<HashTable<DataType, label>, KeyType> combinedTable;
+    HashTable<Map<DataType>, KeyType> combinedTable;
 
     List<HashTableData> procData(Pstream::nProcs(), HashTableData());
 
@@ -90,36 +83,25 @@ void Foam::PrintTable<KeyType, DataType>::print
         {
             const HashTableData& procIData = procData[proci];
 
-            for
-            (
-                typename HashTableData::const_iterator iter = procIData.begin();
-                iter != procIData.end();
-                ++iter
-            )
+            forAllConstIters(procIData, iter)
             {
                 if (!combinedTable.found(iter.key()))
                 {
                     combinedTable.insert
                     (
                         iter.key(),
-                        HashTable<DataType, label>()
+                        Map<DataType>()
                     );
                 }
 
-                HashTable<DataType, label>& key = combinedTable[iter.key()];
+                Map<DataType>& key = combinedTable[iter.key()];
 
-                key.insert(proci, iter());
+                key.insert(proci, iter.object());
 
-                for
-                (
-                    typename HashTable<DataType, label>
-                        ::const_iterator dataIter = key.begin();
-                    dataIter != key.end();
-                    ++dataIter
-                )
+                forAllConstIters(key, dataIter)
                 {
                     std::ostringstream buf;
-                    buf << dataIter();
+                    buf << dataIter.object();
 
                     largestDataLength = max
                     (
@@ -172,7 +154,7 @@ void Foam::PrintTable<KeyType, DataType>::print
 
         forAll(sortedTable, keyI)
         {
-            const HashTable<DataType, label>& procDataList
+            const Map<DataType>& procDataList
                 = combinedTable[sortedTable[keyI]];
 
             os.width(largestKeyLength);
diff --git a/applications/utilities/mesh/generation/foamyMesh/conformalVoronoiMesh/PrintTable/PrintTable.H b/applications/utilities/mesh/generation/foamyMesh/conformalVoronoiMesh/PrintTable/PrintTable.H
index 3f8ddb829b..175d2908d5 100644
--- a/applications/utilities/mesh/generation/foamyMesh/conformalVoronoiMesh/PrintTable/PrintTable.H
+++ b/applications/utilities/mesh/generation/foamyMesh/conformalVoronoiMesh/PrintTable/PrintTable.H
@@ -101,7 +101,7 @@ public:
 
 
     //- Destructor
-    ~PrintTable();
+    ~PrintTable() = default;
 
 
     // Member Functions
diff --git a/applications/utilities/mesh/generation/foamyMesh/conformalVoronoiMesh/conformalVoronoiMesh/featurePointConformer/pointFeatureEdgesTypes.C b/applications/utilities/mesh/generation/foamyMesh/conformalVoronoiMesh/conformalVoronoiMesh/featurePointConformer/pointFeatureEdgesTypes.C
index 8d456f5efd..11586bc54a 100644
--- a/applications/utilities/mesh/generation/foamyMesh/conformalVoronoiMesh/conformalVoronoiMesh/featurePointConformer/pointFeatureEdgesTypes.C
+++ b/applications/utilities/mesh/generation/foamyMesh/conformalVoronoiMesh/conformalVoronoiMesh/featurePointConformer/pointFeatureEdgesTypes.C
@@ -33,18 +33,12 @@ Foam::pointFeatureEdgesTypes::pointFeatureEdgesTypes
     const label pointLabel
 )
 :
-    HashTable<label, extendedFeatureEdgeMesh::edgeStatus>(),
+    HashTable<label, extendedFeatureEdgeMesh::edgeStatus, Hash<label>>(),
     feMesh_(feMesh),
     pointLabel_(pointLabel)
 {}
 
 
-// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
-
-Foam::pointFeatureEdgesTypes::~pointFeatureEdgesTypes()
-{}
-
-
 // * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
 
 Foam::List<Foam::extendedFeatureEdgeMesh::edgeStatus>
@@ -79,18 +73,12 @@ Foam::Ostream& Foam::operator<<
 {
     os  << "Point = " << p.pointLabel_ << endl;
 
-    for
-    (
-        HashTable<label, extendedFeatureEdgeMesh::edgeStatus>
-            ::const_iterator iter = p.cbegin();
-        iter != p.cend();
-        ++iter
-    )
+    forAllConstIters(p, iter)
     {
         os  << "    "
             << extendedFeatureEdgeMesh::edgeStatusNames_[iter.key()]
             << " = "
-            << iter()
+            << iter.object()
             << endl;
     }
 
diff --git a/applications/utilities/mesh/generation/foamyMesh/conformalVoronoiMesh/conformalVoronoiMesh/featurePointConformer/pointFeatureEdgesTypes.H b/applications/utilities/mesh/generation/foamyMesh/conformalVoronoiMesh/conformalVoronoiMesh/featurePointConformer/pointFeatureEdgesTypes.H
index a0b8e2a1fa..765e1e7701 100644
--- a/applications/utilities/mesh/generation/foamyMesh/conformalVoronoiMesh/conformalVoronoiMesh/featurePointConformer/pointFeatureEdgesTypes.H
+++ b/applications/utilities/mesh/generation/foamyMesh/conformalVoronoiMesh/conformalVoronoiMesh/featurePointConformer/pointFeatureEdgesTypes.H
@@ -58,7 +58,7 @@ Ostream& operator<<(Ostream&, const pointFeatureEdgesTypes&);
 //- Hold the types of feature edges attached to the point.
 class pointFeatureEdgesTypes
 :
-    public HashTable<label, extendedFeatureEdgeMesh::edgeStatus>
+    public HashTable<label, extendedFeatureEdgeMesh::edgeStatus, Hash<label>>
 {
     // Private data
 
@@ -82,7 +82,7 @@ public:
 
 
     //- Destructor
-    ~pointFeatureEdgesTypes();
+    ~pointFeatureEdgesTypes() = default;
 
 
     // Member Functions
diff --git a/src/OpenFOAM/containers/HashTables/HashSet/HashSet.H b/src/OpenFOAM/containers/HashTables/HashSet/HashSet.H
index 7574f77592..abf1731cee 100644
--- a/src/OpenFOAM/containers/HashTables/HashSet/HashSet.H
+++ b/src/OpenFOAM/containers/HashTables/HashSet/HashSet.H
@@ -38,7 +38,7 @@ Note
     The HashSet iterator dereferences to the key, so the following
     range-for works as expected:
     \code
-        HashSet<label> someLabels{10, 20, 30, 40, ...};
+        labelHashSet someLabels{10, 20, 30, 40, ...};
         for (const label i : someLabels)
         {
             Info<< "val:" << i << nl;
@@ -55,7 +55,7 @@ Typedef
     Foam::labelHashSet
 
 Description
-    A HashSet with label keys.
+    A HashSet with label keys and label hasher.
 
 \*---------------------------------------------------------------------------*/
 
@@ -415,7 +415,7 @@ HashSet<Key,Hash> operator^
 //- A HashSet with word keys.
 typedef HashSet<> wordHashSet;
 
-//- A HashSet with label keys.
+//- A HashSet with label keys and label hasher.
 typedef HashSet<label, Hash<label>> labelHashSet;
 
 
diff --git a/src/conversion/fire/FIREMeshWriter.C b/src/conversion/fire/FIREMeshWriter.C
index 048dc2afd8..f904f3f9fa 100644
--- a/src/conversion/fire/FIREMeshWriter.C
+++ b/src/conversion/fire/FIREMeshWriter.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 2016 OpenCFD Ltd.
+    \\  /    A nd           | Copyright (C) 2016-2018 OpenCFD Ltd.
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -25,7 +25,7 @@ License
 
 #include "FIREMeshWriter.H"
 #include "Time.H"
-#include "HashTable.H"
+#include "Map.H"
 #include "OFstream.H"
 #include "processorPolyPatch.H"
 
@@ -117,8 +117,8 @@ bool Foam::fileFormats::FIREMeshWriter::writeSelections(OSstream& os) const
 
     // remap name between patches and cell-zones conflicts!
 
-    HashTable<word, label> patchNames;
-    HashTable<word, label> zoneNames;
+    Map<word> patchNames;
+    Map<word> zoneNames;
 
     wordHashSet usedPatchNames;
     wordHashSet usedZoneNames;
@@ -245,12 +245,6 @@ Foam::fileFormats::FIREMeshWriter::FIREMeshWriter
 {}
 
 
-// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
-
-Foam::fileFormats::FIREMeshWriter::~FIREMeshWriter()
-{}
-
-
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
 bool Foam::fileFormats::FIREMeshWriter::write(const fileName& meshName) const
diff --git a/src/conversion/fire/FIREMeshWriter.H b/src/conversion/fire/FIREMeshWriter.H
index 66294b068c..2ead656b52 100644
--- a/src/conversion/fire/FIREMeshWriter.H
+++ b/src/conversion/fire/FIREMeshWriter.H
@@ -103,7 +103,7 @@ public:
 
 
     //- Destructor
-    virtual ~FIREMeshWriter();
+    virtual ~FIREMeshWriter() = default;
 
 
     // Member Functions
diff --git a/src/conversion/vtk/part/foamVtuSizing.C b/src/conversion/vtk/part/foamVtuSizing.C
index 6d12f7447c..07752d63df 100644
--- a/src/conversion/vtk/part/foamVtuSizing.C
+++ b/src/conversion/vtk/part/foamVtuSizing.C
@@ -59,12 +59,6 @@ Foam::vtk::vtuSizing::vtuSizing()
 }
 
 
-// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
-
-Foam::vtk::vtuSizing::~vtuSizing()
-{}
-
-
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
 void Foam::vtk::vtuSizing::reset
@@ -83,7 +77,7 @@ void Foam::vtk::vtuSizing::reset
     const cellShapeList& shapes = mesh.cellShapes();
 
     // Unique vertex labels per polyhedral
-    HashSet<label> hashUniqId(2*256);
+    labelHashSet hashUniqId(2*256);
 
     decompose_ = decompose;
     nCells_    = mesh.nCells();
diff --git a/src/conversion/vtk/part/foamVtuSizing.H b/src/conversion/vtk/part/foamVtuSizing.H
index d09d486f04..b4fb3cab69 100644
--- a/src/conversion/vtk/part/foamVtuSizing.H
+++ b/src/conversion/vtk/part/foamVtuSizing.H
@@ -203,7 +203,7 @@ public:
 
 
     //- Destructor
-    ~vtuSizing();
+    ~vtuSizing() = default;
 
 
     // Member Functions
diff --git a/src/conversion/vtk/part/foamVtuSizingTemplates.C b/src/conversion/vtk/part/foamVtuSizingTemplates.C
index 7f89a44aeb..76133d03a3 100644
--- a/src/conversion/vtk/part/foamVtuSizingTemplates.C
+++ b/src/conversion/vtk/part/foamVtuSizingTemplates.C
@@ -224,7 +224,7 @@ void Foam::vtk::vtuSizing::populateArrays
     const labelList& owner = mesh.faceOwner();
 
     // Unique vertex labels per polyhedral
-    HashSet<label> hashUniqId(2*256);
+    labelHashSet hashUniqId(2*256);
 
     // Index into vertLabels, faceLabels for normal cells
     label nVertLabels = 0;
diff --git a/src/functionObjects/field/particleDistribution/particleDistribution.C b/src/functionObjects/field/particleDistribution/particleDistribution.C
index b8cf35122b..832616f8d1 100644
--- a/src/functionObjects/field/particleDistribution/particleDistribution.C
+++ b/src/functionObjects/field/particleDistribution/particleDistribution.C
@@ -146,7 +146,7 @@ bool Foam::functionObjects::particleDistribution::write()
         // Tag field present - generate distribution per tag
         const IOField<label>& tag =
             cloudObr.lookupObject<IOField<label>>(tagFieldName_);
-        const HashSet<label> tagMap(tag);
+        const labelHashSet tagMap(tag);
         const label tagMax = tagMap.size();
 
         List<DynamicList<label>> tagAddr(tagMax);
diff --git a/src/meshTools/triSurface/triSurfaceTools/triSurfaceTools.C b/src/meshTools/triSurface/triSurfaceTools/triSurfaceTools.C
index 4f0745a184..4b48447d2a 100644
--- a/src/meshTools/triSurface/triSurfaceTools/triSurfaceTools.C
+++ b/src/meshTools/triSurface/triSurfaceTools/triSurfaceTools.C
@@ -451,8 +451,8 @@ void Foam::triSurfaceTools::getMergedEdges
     const triSurface& surf,
     const label edgeI,
     const labelHashSet& collapsedFaces,
-    HashTable<label, label, Hash<label>>& edgeToEdge,
-    HashTable<label, label, Hash<label>>& edgeToFace
+    Map<label>& edgeToEdge,
+    Map<label>& edgeToFace
 )
 {
     const edge& e = surf.edges()[edgeI];
@@ -534,8 +534,8 @@ Foam::scalar Foam::triSurfaceTools::edgeCosAngle
     const label v1,
     const point& pt,
     const labelHashSet& collapsedFaces,
-    const HashTable<label, label, Hash<label>>& edgeToEdge,
-    const HashTable<label, label, Hash<label>>& edgeToFace,
+    const Map<label>& edgeToEdge,
+    const Map<label>& edgeToFace,
     const label facei,
     const label edgeI
 )
@@ -630,8 +630,8 @@ Foam::scalar Foam::triSurfaceTools::collapseMinCosAngle
     const label v1,
     const point& pt,
     const labelHashSet& collapsedFaces,
-    const HashTable<label, label, Hash<label>>& edgeToEdge,
-    const HashTable<label, label, Hash<label>>& edgeToFace
+    const Map<label>& edgeToEdge,
+    const Map<label>& edgeToFace
 )
 {
     const labelList& v1Faces = surf.pointFaces()[v1];
@@ -684,8 +684,8 @@ bool Foam::triSurfaceTools::collapseCreatesFold
     const label v1,
     const point& pt,
     const labelHashSet& collapsedFaces,
-    const HashTable<label, label, Hash<label>>& edgeToEdge,
-    const HashTable<label, label, Hash<label>>& edgeToFace,
+    const Map<label>& edgeToEdge,
+    const Map<label>& edgeToFace,
     const scalar minCos
 )
 {
@@ -749,7 +749,7 @@ bool Foam::triSurfaceTools::collapseCreatesFold
 //    // neighbours actually contains the
 //    // edge with which triangle connects to collapsedFaces.
 //
-//    HashTable<label, label, Hash<label>> neighbours;
+//    Map<label> neighbours;
 //
 //    labelList collapsed = collapsedFaces.toc();
 //
diff --git a/src/meshTools/triSurface/triSurfaceTools/triSurfaceTools.H b/src/meshTools/triSurface/triSurfaceTools/triSurfaceTools.H
index 28960823db..84067be52a 100644
--- a/src/meshTools/triSurface/triSurfaceTools/triSurfaceTools.H
+++ b/src/meshTools/triSurface/triSurfaceTools/triSurfaceTools.H
@@ -54,6 +54,7 @@ SourceFiles
 #include "triadFieldFwd.H"
 #include "DynamicList.H"
 #include "HashSet.H"
+#include "Map.H"
 #include "FixedList.H"
 #include "Pair.H"
 #include "vector2D.H"
@@ -159,8 +160,8 @@ class triSurfaceTools
                 const triSurface& surf,
                 const label edgeI,
                 const labelHashSet& collapsedFaces,
-                HashTable<label, label, Hash<label>>& edgeToEdge,
-                HashTable<label, label, Hash<label>>& edgeToFace
+                Map<label>& edgeToEdge,
+                Map<label>& edgeToFace
             );
 
             //- Calculates (cos of) angle across edgeI of facei,
@@ -172,8 +173,8 @@ class triSurfaceTools
                 const label v1,
                 const point& pt,
                 const labelHashSet& collapsedFaces,
-                const HashTable<label, label, Hash<label>>& edgeToEdge,
-                const HashTable<label, label, Hash<label>>& edgeToFace,
+                const Map<label>& edgeToEdge,
+                const Map<label>& edgeToFace,
                 const label facei,
                 const label edgeI
             );
@@ -188,8 +189,8 @@ class triSurfaceTools
                 const label v1,
                 const point& pt,
                 const labelHashSet& collapsedFaces,
-                const HashTable<label, label, Hash<label>>& edgeToEdge,
-                const HashTable<label, label, Hash<label>>& edgeToFace
+                const Map<label>& edgeToEdge,
+                const Map<label>& edgeToFace
             );
 
             //- Like collapseMinCosAngle but return true for value < minCos
@@ -199,8 +200,8 @@ class triSurfaceTools
                 const label v1,
                 const point& pt,
                 const labelHashSet& collapsedFaces,
-                const HashTable<label, label, Hash<label>>& edgeToEdge,
-                const HashTable<label, label, Hash<label>>& edgeToFace,
+                const Map<label>& edgeToEdge,
+                const Map<label>& edgeToFace,
                 const scalar minCos
             );
 
@@ -210,7 +211,7 @@ class triSurfaceTools
             //(
             //    const triSurface& surf,
             //    const label edgeI,
-            //    const HashTable<bool, label, Hash<label>>& collapsedFaces
+            //    const Map<bool>& collapsedFaces
             //);
 
         // Tracking