diff --git a/applications/test/Tuple2/Test-Tuple2.C b/applications/test/Tuple2/Test-Tuple2.C
index 378d727b6f..2f679b4a31 100644
--- a/applications/test/Tuple2/Test-Tuple2.C
+++ b/applications/test/Tuple2/Test-Tuple2.C
@@ -25,10 +25,11 @@ Application
     Test-Tuple2
 
 Description
+    Test construction, comparision etc for Tuple2 and Pair.
 
 \*---------------------------------------------------------------------------*/
 
-#include "Pair.H"
+#include "labelPair.H"
 #include "Tuple2.H"
 #include "label.H"
 #include "scalar.H"
@@ -67,6 +68,26 @@ struct special2
 };
 
 
+// Print info
+void printTuple2(const Tuple2<word, word>& t)
+{
+    Info<< "tuple: " << t << nl;
+
+    Info<< "first  @: " << long(t.first().data()) << nl;
+    Info<< "second @: " << long(t.second().data()) << nl;
+}
+
+
+// Print info
+void printTuple2(const Pair<word>& t)
+{
+    Info<< "tuple: " << t << nl;
+
+    Info<< "first  @: " << long(t.first().data()) << nl;
+    Info<< "second @: " << long(t.second().data()) << nl;
+}
+
+
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 // Main program:
 
@@ -74,11 +95,14 @@ int main()
 {
     typedef Tuple2<label, scalar> indexedScalar;
 
+    Info<< "null constructed Tuple: " << indexedScalar() << nl;
+    Info<< "null constructed Pair: "  << Pair<scalar>() << nl;
+
     indexedScalar t2(1, 3.2);
 
-    Info<< "tuple: "
+    Info<< "Foam::Tuple2: "
         << t2 << " => "
-        << t2.first() << " " << t2.second() << nl;
+        << t2.first() << ' ' << t2.second() << nl;
 
     // As list. Generated so that we have duplicate indices
     List<indexedScalar> list1(3*4);
@@ -113,25 +137,83 @@ int main()
         << nl << list1 << nl;
 
 
-    Info<< nl << nl << "Pairs" << nl;
+    {
+        Info<< nl << nl << "Foam::Pair" << nl;
 
-    typedef Pair<label> indexedLabel;
+        typedef Pair<label> indexedLabel;
 
-    indexedLabel pr(1, 3);
+        indexedLabel pr(1, 3);
 
-    Info<< "pair: "
-        << pr << " => "
-        << pr.first() << " " << pr.second() << nl;
+        Info<< "pair: "
+            << pr << " => "
+            << pr.first() << ' ' << pr.second() << nl;
 
-    List<indexedLabel> list2 = ListOps::create<indexedLabel>
-    (
-        list1,
-        [](const indexedScalar& t2) {
-            return indexedLabel(t2.first(), t2.second());
-        }
-    );
+        List<indexedLabel> list2 = ListOps::create<indexedLabel>
+        (
+            list1,
+            [](const indexedScalar& t2)
+            {
+                return indexedLabel(t2.first(), t2.second());
+            }
+        );
 
-    Info<< "Unsorted pairs:" << nl << list2 << nl;
+        Info<< "Unsorted pairs:" << nl << list2 << nl;
+    }
+
+
+    {
+        Info<< nl << nl << "std::pair" << nl;
+
+        typedef std::pair<label, label> indexedLabel;
+
+        indexedLabel pr(1, 3);
+
+        Info<< "pair: "
+            << pr << " => "
+            << pr.first << ' ' << pr.second << nl;
+
+        List<indexedLabel> list2 = ListOps::create<indexedLabel>
+        (
+            list1,
+            [](const indexedScalar& t2)
+            {
+                return indexedLabel(t2.first(), t2.second());
+            }
+        );
+
+        Info<< "Unsorted pairs:" << nl << list2 << nl;
+    }
+
+
+    {
+        word word1("hello");
+        word word2("word");
+
+        Info<< "create with " << word1 << " @ " << long(word1.data())
+            << " " << word2 << " @ " << long(word2.data()) << nl;
+
+        Tuple2<word, word> tup(std::move(word2), std::move(word1));
+
+        printTuple2(tup);
+
+        Info<< "input is now " << word1 << " @ " << long(word1.data())
+            << " " << word2 << " @ " << long(word2.data()) << nl;
+    }
+
+    {
+        word word1("hello");
+        word word2("word");
+
+        Info<< "create with " << word1 << " @ " << long(word1.data())
+            << " " << word2 << " @ " << long(word2.data()) << nl;
+
+        Pair<word> tup(std::move(word2), std::move(word1));
+
+        printTuple2(tup);
+
+        Info<< "input is now " << word1 << " @ " << long(word1.data())
+            << " " << word2 << " @ " << long(word2.data()) << nl;
+    }
 
     Info<< "\nEnd\n" << endl;
 
diff --git a/src/OpenFOAM/primitives/Pair/Pair.H b/src/OpenFOAM/primitives/Pair/Pair.H
index cd64a9cf5d..61e19afb5f 100644
--- a/src/OpenFOAM/primitives/Pair/Pair.H
+++ b/src/OpenFOAM/primitives/Pair/Pair.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) 2017-2018 OpenCFD Ltd.
+     \\/     M anipulation  | Copyright (C) 2017-2019 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -41,6 +41,7 @@ See also
 
 #include "FixedList.H"
 #include "Istream.H"
+#include <utility>
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -64,17 +65,26 @@ public:
         //- Construct null
         Pair() = default;
 
-        //- Construct from components
+        //- Copy construct from components
         inline Pair(const T& f, const T& s);
 
-        //- Construct from FixedList
-        inline Pair(const FixedList<T, 2>& lst);
+        //- Move construct from components
+        inline Pair(T&& f, T&& s);
 
-        //- Construct, optionally sorted with first less-than second
+        //- Copy construct from std::pair
+        inline Pair(const std::pair<T,T>& vals);
+
+        //- Move construct from std::pair
+        inline Pair(std::pair<T,T>&& vals);
+
+        //- Copy construct FixedList of two items
+        inline Pair(const FixedList<T, 2>& list);
+
+        //- Copy construct, optionally sorted with first less-than second
         inline Pair(const T& f, const T& s, const bool doSort);
 
-        //- Construct, optionally sorted with first less-than second
-        inline Pair(const FixedList<T, 2>& lst, const bool doSort);
+        //- Copy construct, optionally sorted with first less-than second
+        inline Pair(const FixedList<T, 2>& list, const bool doSort);
 
         //- Construct from Istream
         inline explicit Pair(Istream& is);
@@ -151,6 +161,7 @@ public:
                 return seed;
             }
         };
+
 };
 
 
@@ -206,11 +217,7 @@ bool operator<(const Pair<T>& a, const Pair<T>& b)
     return
     (
         a.first() < b.first()
-     ||
-        (
-            !(b.first() < a.first())
-         && a.second() < b.second()
-        )
+     || (!(b.first() < a.first()) && a.second() < b.second())
     );
 }
 
diff --git a/src/OpenFOAM/primitives/Pair/PairI.H b/src/OpenFOAM/primitives/Pair/PairI.H
index 7b236595ac..de82a7a7e6 100644
--- a/src/OpenFOAM/primitives/Pair/PairI.H
+++ b/src/OpenFOAM/primitives/Pair/PairI.H
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
-    \\  /    A nd           | Copyright (C) 2017 OpenCFD Ltd.
+    \\  /    A nd           | Copyright (C) 2017-2019 OpenCFD Ltd.
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -54,9 +54,33 @@ inline Foam::Pair<T>::Pair(const T& f, const T& s)
 
 
 template<class T>
-inline Foam::Pair<T>::Pair(const FixedList<T, 2>& lst)
+inline Foam::Pair<T>::Pair(T&& f, T&& s)
+{
+    first()  = std::move(f);
+    second() = std::move(s);
+}
+
+
+template<class T>
+inline Foam::Pair<T>::Pair(const std::pair<T,T>& vals)
+{
+    first()  = vals.first;
+    second() = vals.second;
+}
+
+
+template<class T>
+inline Foam::Pair<T>::Pair(std::pair<T,T>&& vals)
+{
+    first()  = std::move(vals.first);
+    second() = std::move(vals.second);
+}
+
+
+template<class T>
+inline Foam::Pair<T>::Pair(const FixedList<T, 2>& list)
 :
-    FixedList<T, 2>(lst)
+    FixedList<T, 2>(list)
 {}
 
 
@@ -77,13 +101,12 @@ 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>& lst, const bool doSort)
+inline Foam::Pair<T>::Pair(const FixedList<T, 2>& list, const bool doSort)
 :
-    Pair<T>(lst.first(), lst.last(), doSort)
+    Pair<T>(list.first(), list.last(), doSort)
 {}
 
 
-
 template<class T>
 inline Foam::Pair<T>::Pair(Istream& is)
 :
@@ -132,16 +155,16 @@ inline const T& Foam::Pair<T>::other(const T& a) const
 
 
 template<class T>
-inline bool Foam::Pair<T>::sorted() const
+inline void Foam::Pair<T>::flip()
 {
-    return (first() < second());
+    Foam::Swap(first(), second());
 }
 
 
 template<class T>
-inline void Foam::Pair<T>::flip()
+inline bool Foam::Pair<T>::sorted() const
 {
-    Foam::Swap(first(), second());
+    return !(second() < first());
 }
 
 
diff --git a/src/OpenFOAM/primitives/Tuple2/Tuple2.H b/src/OpenFOAM/primitives/Tuple2/Tuple2.H
index 78e71d168d..eba427ae00 100644
--- a/src/OpenFOAM/primitives/Tuple2/Tuple2.H
+++ b/src/OpenFOAM/primitives/Tuple2/Tuple2.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  |
+     \\/     M anipulation  | Copyright (C) 2019 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -38,45 +38,35 @@ See also
 #define Tuple2_H
 
 #include "Istream.H"
+#include "Ostream.H"
+#include <utility>
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 namespace Foam
 {
 
-// Forward declarations
-
-template<class Type1, class Type2>
-class Tuple2;
-
-template<class Type1, class Type2>
-inline Istream& operator>>(Istream& is, Tuple2<Type1, Type2>& t2);
-
-template<class Type1, class Type2>
-inline Ostream& operator<<(Ostream& os, const Tuple2<Type1, Type2>& t2);
-
-
 /*---------------------------------------------------------------------------*\
                            Class Tuple2 Declaration
 \*---------------------------------------------------------------------------*/
 
-template<class Type1, class Type2>
+template<class T1, class T2>
 class Tuple2
 {
-    // Private data
+    // Private Data
 
-        Type1 f_;
-        Type2 s_;
+        T1 f_;
+        T2 s_;
 
 public:
 
     // Typedefs (cf. std::pair)
 
-        //- Type of member first, the first template parameter (Type1)
-        typedef Type1 first_type;
+        //- Type of member first, the first template parameter (T1)
+        typedef T1 first_type;
 
-        //- Type of member second, the second template parameter (Type2)
-        typedef Type2 second_type;
+        //- Type of member second, the second template parameter (T2)
+        typedef T2 second_type;
 
 
     // Constructors
@@ -84,13 +74,34 @@ public:
         //- Construct null
         inline Tuple2() = default;
 
-        //- Construct from components
-        inline Tuple2(const Type1& f, const Type2& s)
+        //- Copy construct from components
+        inline Tuple2(const T1& f, const T2& s)
         :
             f_(f),
             s_(s)
         {}
 
+        //- Move construct from components
+        inline Tuple2(T1&& f, T2&& s)
+        :
+            f_(std::move(f)),
+            s_(std::move(s))
+        {}
+
+        //- Copy construct from std::pair
+        inline Tuple2(const std::pair<T1,T2>& vals)
+        :
+            f_(vals.first),
+            s_(vals.second)
+        {}
+
+        //- Move construct from std::pair
+        inline Tuple2(std::pair<T1,T2>&& vals)
+        :
+            f_(std::move(vals.first)),
+            s_(std::move(vals.second))
+        {}
+
         //- Construct from Istream
         inline explicit Tuple2(Istream& is)
         {
@@ -101,136 +112,94 @@ public:
     // Member Functions
 
         //- Return first
-        inline const Type1& first() const
+        inline const T1& first() const
         {
             return f_;
         }
 
         //- Return first
-        inline Type1& first()
+        inline T1& first()
         {
             return f_;
         }
 
         //- Return second
-        inline const Type2& second() const
+        inline const T2& second() const
         {
             return s_;
         }
 
         //- Return second
-        inline Type2& second()
+        inline T2& second()
         {
             return s_;
         }
-
-
-    // IOstream operators
-
-        //- Read Tuple2 from Istream, discarding contents of existing Tuple2.
-        friend Istream& operator>> <Type1, Type2>
-        (
-            Istream& is,
-            Tuple2<Type1, Type2>& t2
-        );
-
-        // Write Tuple2 to Ostream.
-        friend Ostream& operator<< <Type1, Type2>
-        (
-            Ostream& os,
-            const Tuple2<Type1, Type2>& t2
-        );
 };
 
 
 //- Return reverse of a Tuple2
-template<class Type1, class Type2>
-inline Tuple2<Type2, Type1> reverse(const Tuple2<Type1, Type2>& t)
+template<class T1, class T2>
+inline Tuple2<T2, T1> reverse(const Tuple2<T1,T2>& t)
 {
-    return Tuple2<Type2, Type1>(t.second(), t.first());
+    return Tuple2<T2, T1>(t.second(), t.first());
 }
 
 
-template<class Type1, class Type2>
-inline bool operator==
-(
-    const Tuple2<Type1, Type2>& a,
-    const Tuple2<Type1, Type2>& b
-)
+template<class T1, class T2>
+inline bool operator==(const Tuple2<T1,T2>& a, const Tuple2<T1,T2>& b)
 {
     return (a.first() == b.first() && a.second() == b.second());
 }
 
 
-template<class Type1, class Type2>
-inline bool operator!=
-(
-    const Tuple2<Type1, Type2>& a,
-    const Tuple2<Type1, Type2>& b
-)
+template<class T1, class T2>
+inline bool operator!=(const Tuple2<T1,T2>& a, const Tuple2<T1,T2>& b)
 {
     return !(a == b);
 }
 
 
-template<class Type1, class Type2>
-inline bool operator<
-(
-    const Tuple2<Type1, Type2>& a,
-    const Tuple2<Type1, Type2>& b
-)
+template<class T1, class T2>
+inline bool operator<(const Tuple2<T1,T2>& a, const Tuple2<T1,T2>& b)
 {
     return
     (
         a.first() < b.first()
-     ||
-        (
-            !(b.first() < a.first())
-         && a.second() < b.second()
-        )
+     || (!(b.first() < a.first()) && a.second() < b.second())
     );
 }
 
 
 
-template<class Type1, class Type2>
-inline bool operator<=
-(
-    const Tuple2<Type1, Type2>& a,
-    const Tuple2<Type1, Type2>& b
-)
+template<class T1, class T2>
+inline bool operator<=(const Tuple2<T1,T2>& a, const Tuple2<T1,T2>& b)
 {
     return !(b < a);
 }
 
 
-template<class Type1, class Type2>
-inline bool operator>
-(
-    const Tuple2<Type1, Type2>& a,
-    const Tuple2<Type1, Type2>& b
-)
+template<class T1, class T2>
+inline bool operator>(const Tuple2<T1,T2>& a, const Tuple2<T1,T2>& b)
 {
     return (b < a);
 }
 
 
-template<class Type1, class Type2>
-inline bool operator>=
-(
-    const Tuple2<Type1, Type2>& a,
-    const Tuple2<Type1, Type2>& b
-)
+template<class T1, class T2>
+inline bool operator>=(const Tuple2<T1,T2>& a, const Tuple2<T1,T2>& b)
 {
     return !(a < b);
 }
 
 
-template<class Type1, class Type2>
-inline Istream& operator>>(Istream& is, Tuple2<Type1, Type2>& t2)
+// IOstream Operators
+
+//- Read Tuple2 from Istream, discarding contents of existing Tuple2.
+template<class T1, class T2>
+inline Istream& operator>>(Istream& is, Tuple2<T1,T2>& t)
 {
     is.readBegin("Tuple2");
-    is >> t2.f_ >> t2.s_;
+    is >> t.first() >> t.second();
     is.readEnd("Tuple2");
 
     is.check(FUNCTION_NAME);
@@ -238,11 +207,37 @@ inline Istream& operator>>(Istream& is, Tuple2<Type1, Type2>& t2)
 }
 
 
-template<class Type1, class Type2>
-inline Ostream& operator<<(Ostream& os, const Tuple2<Type1, Type2>& t2)
+//- Read std::pair from Istream
+template<class T1, class T2>
+inline Istream& operator>>(Istream& is, std::pair<T1,T2>& t)
+{
+    is.readBegin("std::pair");
+    is >> t.first >> t.second;
+    is.readEnd("std::pair");
+
+    is.check(FUNCTION_NAME);
+    return is;
+}
+
+
+//- Write Tuple2 to Ostream.
+template<class T1, class T2>
+inline Ostream& operator<<(Ostream& os, const Tuple2<T1,T2>& t)
 {
     os  << token::BEGIN_LIST
-        << t2.f_ << token::SPACE << t2.s_
+        << t.first() << token::SPACE << t.second()
+        << token::END_LIST;
+
+    return os;
+}
+
+
+//- Write std::pair to Ostream.
+template<class T1, class T2>
+inline Ostream& operator<<(Ostream& os, const std::pair<T1,T2>& t)
+{
+    os  << token::BEGIN_LIST
+        << t.first << token::SPACE << t.second
         << token::END_LIST;
 
     return os;