From 23b6ea4b855ca2367c0ad12b32d12da65c8b530f Mon Sep 17 00:00:00 2001
From: Mark Olesen <Mark.Olesen@esi-group.com>
Date: Wed, 7 Mar 2018 17:50:34 +0100
Subject: [PATCH] ENH: provide iterators for IndirectList, UIndirectList

- consistency with other containers.
  Allows range-for, enables various std algorithms, and can be used
  with ListOp::create() with an iterator range.
---
 .../test/IndirectList/Test-IndirectList.C     |   7 +
 .../Lists/IndirectList/IndirectList.H         |  39 ++--
 .../Lists/IndirectList/IndirectListI.H        |  20 +-
 .../Lists/UIndirectList/UIndirectList.C       |  10 +-
 .../Lists/UIndirectList/UIndirectList.H       | 197 +++++++++++++++---
 .../Lists/UIndirectList/UIndirectListI.H      |  52 ++---
 .../Lists/UIndirectList/UIndirectListIO.C     |   4 +-
 7 files changed, 230 insertions(+), 99 deletions(-)

diff --git a/applications/test/IndirectList/Test-IndirectList.C b/applications/test/IndirectList/Test-IndirectList.C
index 64ac880e0b..25b95990fb 100644
--- a/applications/test/IndirectList/Test-IndirectList.C
+++ b/applications/test/IndirectList/Test-IndirectList.C
@@ -41,6 +41,13 @@ void printInfo(const ListType& lst)
         << "addr: " << flatOutput(lst.addressing()) << nl
         << "list: " << flatOutput(lst) << nl
         << endl;
+
+    Info<<"for-range :";
+    for (const auto& val : lst)
+    {
+        Info<< " " << val;
+    }
+    Info<< nl;
 }
 
 
diff --git a/src/OpenFOAM/containers/Lists/IndirectList/IndirectList.H b/src/OpenFOAM/containers/Lists/IndirectList/IndirectList.H
index 1422a03674..042c2044d9 100644
--- a/src/OpenFOAM/containers/Lists/IndirectList/IndirectList.H
+++ b/src/OpenFOAM/containers/Lists/IndirectList/IndirectList.H
@@ -61,10 +61,10 @@ class IndirectListAddressing
 
     // Private Member Functions
 
-        //- Disallow default bitwise copy construct
+        //- Disallow copy construct
         IndirectListAddressing(const IndirectListAddressing&) = delete;
 
-        //- Disallow default bitwise assignment
+        //- Disallow copy assignment
         void operator=(const IndirectListAddressing&) = delete;
 
 
@@ -72,10 +72,10 @@ protected:
 
     // Constructors
 
-        //- Construct by copying the addressing array
+        //- Copy construct from addressing array
         explicit inline IndirectListAddressing(const labelUList& addr);
 
-        //- Construct by transferring addressing array
+        //- Move construct from addressing array
         explicit inline IndirectListAddressing(List<label>&& addr);
 
 
@@ -105,10 +105,10 @@ class IndirectList
 {
     // Private Member Functions
 
-        //- Disallow default assignment operator
+        //- Disallow copy construct
         void operator=(const IndirectList<T>&) = delete;
 
-        //- Disallow assignment from UIndirectList
+        //- Disallow copy assignment
         void operator=(const UIndirectList<T>&) = delete;
 
 
@@ -116,25 +116,18 @@ public:
 
     // Constructors
 
-        //- Construct given the complete list and the addressing array
-        inline IndirectList
-        (
-            const UList<T>& completeList,
-            const labelUList& addr
-        );
+        //- Copy construct addressing, shallow copy values list reference.
+        inline IndirectList(const UList<T>& values, const labelUList& addr);
 
-        //- Construct given the complete list and by transferring addressing
-        inline IndirectList
-        (
-            const UList<T>& completeList,
-            List<label>&& addr
-        );
+        //- Move construct addressing, shallow copy values list reference.
+        inline IndirectList(const UList<T>& values, List<label>&& addr);
 
-        //- Copy constructor
-        inline IndirectList(const IndirectList<T>& lst);
+        //- Copy construct addressing, shallow copy values list reference.
+        inline IndirectList(const IndirectList<T>& list);
 
-        //- Construct from UIndirectList
-        explicit inline IndirectList(const UIndirectList<T>& lst);
+        //- Copy construct addressing, shallow copy values list reference
+        //- from UIndirectList
+        explicit inline IndirectList(const UIndirectList<T>& list);
 
 
     // Member Functions
@@ -142,7 +135,7 @@ public:
         //- Return the list addressing
         using UIndirectList<T>::addressing;
 
-        //- Reset addressing
+        //- Reset the list addressing
         using IndirectListAddressing::resetAddressing;
 
 
diff --git a/src/OpenFOAM/containers/Lists/IndirectList/IndirectListI.H b/src/OpenFOAM/containers/Lists/IndirectList/IndirectListI.H
index 27eb6ced04..a4961b7913 100644
--- a/src/OpenFOAM/containers/Lists/IndirectList/IndirectListI.H
+++ b/src/OpenFOAM/containers/Lists/IndirectList/IndirectListI.H
@@ -46,14 +46,14 @@ inline Foam::IndirectListAddressing::IndirectListAddressing
 template<class T>
 inline Foam::IndirectList<T>::IndirectList
 (
-    const UList<T>& completeList,
+    const UList<T>& values,
     const labelUList& addr
 )
 :
     IndirectListAddressing(addr),
     UIndirectList<T>
     (
-        completeList,
+        values,
         IndirectListAddressing::addressing()
     )
 {}
@@ -62,14 +62,14 @@ inline Foam::IndirectList<T>::IndirectList
 template<class T>
 inline Foam::IndirectList<T>::IndirectList
 (
-    const UList<T>& completeList,
+    const UList<T>& values,
     List<label>&& addr
 )
 :
     IndirectListAddressing(std::move(addr)),
     UIndirectList<T>
     (
-        completeList,
+        values,
         IndirectListAddressing::addressing()
     )
 {}
@@ -78,13 +78,13 @@ inline Foam::IndirectList<T>::IndirectList
 template<class T>
 inline Foam::IndirectList<T>::IndirectList
 (
-    const IndirectList<T>& lst
+    const IndirectList<T>& list
 )
 :
-    IndirectListAddressing(lst.addressing()),
+    IndirectListAddressing(list.addressing()),  // Copy addressing
     UIndirectList<T>
     (
-        lst.completeList(),
+        list.completeList(),
         IndirectListAddressing::addressing()
     )
 {}
@@ -93,13 +93,13 @@ inline Foam::IndirectList<T>::IndirectList
 template<class T>
 inline Foam::IndirectList<T>::IndirectList
 (
-    const UIndirectList<T>& lst
+    const UIndirectList<T>& list
 )
 :
-    IndirectListAddressing(lst.addressing()),
+    IndirectListAddressing(list.addressing()),  // Copy addressing
     UIndirectList<T>
     (
-        lst.completeList(),
+        list.completeList(),
         IndirectListAddressing::addressing()
     )
 {}
diff --git a/src/OpenFOAM/containers/Lists/UIndirectList/UIndirectList.C b/src/OpenFOAM/containers/Lists/UIndirectList/UIndirectList.C
index 931e93efb1..68eb148024 100644
--- a/src/OpenFOAM/containers/Lists/UIndirectList/UIndirectList.C
+++ b/src/OpenFOAM/containers/Lists/UIndirectList/UIndirectList.C
@@ -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) 2017-2018 OpenCFD Ltd.
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -34,14 +34,14 @@ inline Foam::label Foam::UIndirectList<T>::find
 {
     if (start >= 0)
     {
-        List_CONST_ACCESS(T, completeList_, lst);
+        List_CONST_ACCESS(T, values_, vals);
         List_CONST_ACCESS(label, addressing_, addr);
 
         const label len = addressing_.size();
 
         for (label i = start; i < len; ++i)
         {
-            if (lst[addr[i]] == val)
+            if (vals[addr[i]] == val)
             {
                 return i;
             }
@@ -59,7 +59,7 @@ inline Foam::label Foam::UIndirectList<T>::rfind
     const label pos
 ) const
 {
-    List_CONST_ACCESS(T, completeList_, lst);
+    List_CONST_ACCESS(T, values_, vals);
     List_CONST_ACCESS(label, addressing_, addr);
 
     for
@@ -74,7 +74,7 @@ inline Foam::label Foam::UIndirectList<T>::rfind
         --i
     )
     {
-        if (lst[addr[i]] == val)
+        if (vals[addr[i]] == val)
         {
             return i;
         }
diff --git a/src/OpenFOAM/containers/Lists/UIndirectList/UIndirectList.H b/src/OpenFOAM/containers/Lists/UIndirectList/UIndirectList.H
index 2fb26f4a36..e8e0f30c38 100644
--- a/src/OpenFOAM/containers/Lists/UIndirectList/UIndirectList.H
+++ b/src/OpenFOAM/containers/Lists/UIndirectList/UIndirectList.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 OpenCFD Ltd.
+     \\/     M anipulation  | Copyright (C) 2017-2018 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -29,7 +29,7 @@ Description
 
     Like IndirectList but does not store addressing.
 
-    Note the const_cast of the completeList. This is so we can use it both
+    Note the const_cast of the list values. This is so we can use it both
     on const and non-const lists. Alternative would be to have a const_
     variant etc.
 
@@ -48,7 +48,7 @@ SourceFiles
 namespace Foam
 {
 
-// Forward declaration of friend functions and operators
+// Forward declarations
 template<class T> class UIndirectList;
 template<class T> Ostream& operator<<(Ostream&, const UIndirectList<T>&);
 
@@ -65,25 +65,50 @@ class UIndirectList
 {
     // Private data
 
-        UList<T>& completeList_;
+        UList<T>& values_;
         const labelUList& addressing_;
 
-
 public:
 
+    // STL type definitions
+
+        //- Type of values the list contains.
+        typedef T value_type;
+
+        //- The pointer type for non-const access to value_type items
+        typedef T* pointer;
+
+        //- The pointer type for const access to value_type items
+        typedef const T* const_pointer;
+
+        //- The type used for storing into value_type objects
+        typedef T& reference;
+
+        //- The type used for reading from constant value_type objects.
+        typedef const T& const_reference;
+
+        //- The type to represent the size of a UList
+        typedef label size_type;
+
+        //- The difference between iterator objects
+        typedef label difference_type;
+
+        //- Forward iterator with non-const access
+        class iterator;
+
+        //- Forward iterator with const access
+        class const_iterator;
+
+
     // Constructors
 
-        //- Construct given the complete list and the addressing array
-        inline UIndirectList
-        (
-            const UList<T>& completeList,
-            const labelUList& addr
-        );
+        //- Copy construct from the values list and the addressing array
+        inline UIndirectList(const UList<T>& values, const labelUList& addr);
 
 
     // Member Functions
 
-      // Access
+    // Access
 
         //- Return the number of elements in the list
         inline label size() const;
@@ -103,14 +128,14 @@ public:
         //- Return the last element of the list.
         inline const T& last() const;
 
-        //- Return the complete list
+        //- Return the complete list of values
         inline const UList<T>& completeList() const;
 
         //- Return the list addressing
         inline const List<label>& addressing() const;
 
 
-      // Search
+    // Search
 
         //- Find index of the first occurence of the value.
         //  When start is specified, any occurences before start are ignored.
@@ -139,38 +164,142 @@ public:
         //- Return const access to an element
         inline const T& operator[](const label i) const;
 
-        //- Assignment to UList of addressed elements
-        inline void operator=(const UList<T>& ae);
+        //- Copy assignment from a list of the addressed elements
+        inline void operator=(const UList<T>& rhs);
 
-        //- Assignment to UIndirectList of addressed elements
-        inline void operator=(const UIndirectList<T>& ae);
+        //- Copy assignment from a indirect list of the addressed elements
+        inline void operator=(const UIndirectList<T>& rhs);
 
         //- Assignment of all entries to the given value
-        inline void operator=(const T& t);
+        inline void operator=(const T& val);
+
+        //- An iterator for an indirect list
+        class iterator
+        {
+            typename UList<T>::pointer data_;
+            labelUList::const_iterator base_;
+
+        public:
+
+            iterator
+            (
+                UList<T>& list,
+                labelUList::const_iterator baseIter
+            )
+            :
+                data_(list.begin()),
+                base_(baseIter)
+            {}
+
+            reference operator*() const
+            {
+                return data_[*base_];
+            }
+
+            iterator& operator++()
+            {
+                ++base_;
+                return *this;
+            }
+
+            bool operator==(iterator& rhs) const
+            {
+                return base_ == rhs.base_;
+            }
+
+            bool operator!=(iterator& rhs) const
+            {
+                return (base_ != rhs.base_);
+            }
+        };
 
 
-    // STL type definitions
+        //- A const iterator for an indirect list
+        class const_iterator
+        {
+            typename UList<T>::const_pointer data_;
+            labelUList::const_iterator base_;
 
-        //- Type of values the list contains.
-        typedef T value_type;
+        public:
 
-        //- The type used for storing into UList::value_type objects.
-        typedef T& reference;
+            const_iterator
+            (
+                const UList<T>& list,
+                labelUList::const_iterator baseIter
+            )
+            :
+                data_(list.begin()),
+                base_(baseIter)
+            {}
 
-        //- The type used for reading from constant UList::value_type objects
-        typedef const T& const_reference;
+            const_reference operator*() const
+            {
+                return data_[*base_];
+            }
 
-        //- The type that can represent the difference between any two
-        //- UList iterator objects.
-        typedef label difference_type;
+            const_iterator& operator++()
+            {
+                ++base_;
+                return *this;
+            }
 
-        //- The type that can represent the size of a UList.
-        typedef label size_type;
+            bool operator==(const_iterator& rhs) const
+            {
+                return base_ == rhs.base_;
+            }
+
+            bool operator!=(const_iterator& rhs) const
+            {
+                return base_ != rhs.base_;
+            }
+        };
+
+
+    // iterator (non-const)
+
+        //- Return an iterator at begin of list
+        inline iterator begin()
+        {
+            return iterator(values_, addressing_.cbegin());
+        }
+
+        //- Return an iterator at end of list
+        inline iterator end()
+        {
+            return iterator(values_, addressing_.cend());
+        }
+
+
+    // iterator (const)
+
+        //- Return a const_iterator at begin of list
+        inline const_iterator cbegin() const
+        {
+            return const_iterator(values_, addressing_.cbegin());
+        }
+
+        //- Return a const_iterator at end of list
+        inline const_iterator cend() const
+        {
+            return const_iterator(values_, addressing_.cend());
+        }
+
+        //- Return a const_iterator at end of list
+        inline const_iterator begin() const
+        {
+            return cbegin();
+        }
+
+        //- Return a const_iterator at end of list
+        inline const_iterator end() const
+        {
+            return cend();
+        }
 
 
     // Writing
 
-        //- Write the List, with line-breaks in ASCII if the list length
+        //- Write the list, with line-breaks in ASCII if its length
         //- exceeds shortListLen.
         //  Using '0' suppresses line-breaks entirely.
         Ostream& writeList(Ostream& os, const label shortListLen=0) const;
@@ -178,11 +307,11 @@ public:
 
     // Ostream operator
 
-        //- Write List to Ostream, as per writeList() with shortListLen=10
+        //- Write list to Ostream, as per writeList() with shortListLen=10
         friend Ostream& operator<< <T>
         (
             Ostream& os,
-            const UIndirectList<T>& lst
+            const UIndirectList<T>& list
         );
 };
 
diff --git a/src/OpenFOAM/containers/Lists/UIndirectList/UIndirectListI.H b/src/OpenFOAM/containers/Lists/UIndirectList/UIndirectListI.H
index 15daa10969..47d88a7db2 100644
--- a/src/OpenFOAM/containers/Lists/UIndirectList/UIndirectListI.H
+++ b/src/OpenFOAM/containers/Lists/UIndirectList/UIndirectListI.H
@@ -3,7 +3,7 @@
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
     \\  /    A nd           | Copyright (C) 2011-2015 OpenFOAM Foundation
-     \\/     M anipulation  |
+     \\/     M anipulation  | Copyright (C) 2018 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -28,11 +28,11 @@ License
 template<class T>
 inline Foam::UIndirectList<T>::UIndirectList
 (
-    const UList<T>& completeList,
+    const UList<T>& values,
     const labelUList& addr
 )
 :
-    completeList_(const_cast<UList<T>&>(completeList)),
+    values_(const_cast<UList<T>&>(values)),
     addressing_(addr)
 {}
 
@@ -56,35 +56,35 @@ inline bool Foam::UIndirectList<T>::empty() const
 template<class T>
 inline T& Foam::UIndirectList<T>::first()
 {
-    return completeList_[addressing_.first()];
+    return values_[addressing_.first()];
 }
 
 
 template<class T>
 inline const T& Foam::UIndirectList<T>::first() const
 {
-    return completeList_[addressing_.first()];
+    return values_[addressing_.first()];
 }
 
 
 template<class T>
 inline T& Foam::UIndirectList<T>::last()
 {
-    return completeList_[addressing_.last()];
+    return values_[addressing_.last()];
 }
 
 
 template<class T>
 inline const T& Foam::UIndirectList<T>::last() const
 {
-    return completeList_[addressing_.last()];
+    return values_[addressing_.last()];
 }
 
 
 template<class T>
 inline const Foam::UList<T>& Foam::UIndirectList<T>::completeList() const
 {
-    return completeList_;
+    return values_;
 }
 
 
@@ -125,61 +125,63 @@ inline Foam::List<T> Foam::UIndirectList<T>::operator()() const
 template<class T>
 inline T& Foam::UIndirectList<T>::operator[](const label i)
 {
-    return completeList_[addressing_[i]];
+    return values_[addressing_[i]];
 }
 
 
 template<class T>
 inline const T& Foam::UIndirectList<T>::operator[](const label i) const
 {
-    return completeList_[addressing_[i]];
+    return values_[addressing_[i]];
 }
 
 
 template<class T>
-inline void Foam::UIndirectList<T>::operator=(const UList<T>& ae)
+inline void Foam::UIndirectList<T>::operator=(const UList<T>& rhs)
 {
-    if (addressing_.size() != ae.size())
+    const label len = addressing_.size();
+
+    if (len != rhs.size())
     {
         FatalErrorInFunction
             << "Addressing and list of addressed elements "
-               "have different sizes: "
-            << addressing_.size() << " " << ae.size()
+               "have different sizes: " << len << " " << rhs.size()
             << abort(FatalError);
     }
 
-    forAll(addressing_, i)
+    for (label i = 0; i < len; ++i)
     {
-        completeList_[addressing_[i]] = ae[i];
+        values_[addressing_[i]] = rhs[i];
     }
 }
 
 
 template<class T>
-inline void Foam::UIndirectList<T>::operator=(const UIndirectList<T>& ae)
+inline void Foam::UIndirectList<T>::operator=(const UIndirectList<T>& rhs)
 {
-    if (addressing_.size() != ae.size())
+    const label len = addressing_.size();
+
+    if (len != rhs.size())
     {
         FatalErrorInFunction
             << "Addressing and list of addressed elements "
-               "have different sizes: "
-            << addressing_.size() << " " << ae.size()
+               "have different sizes: " << len << " " << rhs.size()
             << abort(FatalError);
     }
 
-    forAll(addressing_, i)
+    for (label i = 0; i < len; ++i)
     {
-        completeList_[addressing_[i]] = ae[i];
+        values_[addressing_[i]] = rhs[i];
     }
 }
 
 
 template<class T>
-inline void Foam::UIndirectList<T>::operator=(const T& t)
+inline void Foam::UIndirectList<T>::operator=(const T& val)
 {
-    forAll(addressing_, i)
+    for (const label idx : addressing_)
     {
-        completeList_[addressing_[i]] = t;
+        values_[idx] = val;
     }
 }
 
diff --git a/src/OpenFOAM/containers/Lists/UIndirectList/UIndirectListIO.C b/src/OpenFOAM/containers/Lists/UIndirectList/UIndirectListIO.C
index df0e3d6d65..9f3b8bbfa6 100644
--- a/src/OpenFOAM/containers/Lists/UIndirectList/UIndirectListIO.C
+++ b/src/OpenFOAM/containers/Lists/UIndirectList/UIndirectListIO.C
@@ -140,10 +140,10 @@ template<class T>
 Foam::Ostream& Foam::operator<<
 (
     Foam::Ostream& os,
-    const Foam::UIndirectList<T>& lst
+    const Foam::UIndirectList<T>& list
 )
 {
-    return lst.writeList(os, 10);
+    return list.writeList(os, 10);
 }