From a0bba7495016b14c4d7b75d31dfac5bb078f727c Mon Sep 17 00:00:00 2001
From: Mark Olesen <Mark.Olesen@esi-group.com>
Date: Wed, 14 May 2025 11:47:14 +0200
Subject: [PATCH] STYLE: remove old (__cplusplus >= 201703L) checks

- now using c++17 throughout
---
 applications/test/Hashing2/Make/files         |   2 +-
 .../{Test-Hashing2.C => Test-Hashing2.cxx}    |   4 +-
 applications/test/ICharStream1/Make/files     |   2 +-
 ...t-ICharStream1.C => Test-ICharStream1.cxx} |  15 +--
 applications/test/ITstream/Test-ITstream.cxx  |   7 +-
 .../{Test-ListRead1.C => Test-ListRead1.cxx}  |   4 +-
 applications/test/OCharStream1/Make/files     |   2 +-
 ...t-OCharStream1.C => Test-OCharStream1.cxx} |  15 +--
 applications/test/SpanStream1/Make/files      |   2 +-
 ...est-SpanStream1.C => Test-SpanStream1.cxx} |  15 +--
 applications/test/dictionaryTokens/Make/files |   4 +-
 ...naryTokens.C => Test-dictionaryTokens.cxx} |   0
 ...ictionaryTokens.C => dictionaryTokens.cxx} |   0
 applications/test/string_view1/Make/files     |   2 +-
 ...t-string_view1.C => Test-string_view1.cxx} |   7 --
 applications/test/token/Test-token.cxx        | 106 +++++++++---------
 applications/test/tokenize/Make/files         |   2 +-
 .../{Test-tokenize.C => Test-tokenize.cxx}    |   0
 src/OpenFOAM/db/IOstreams/IOstreams/Ostream.H |   2 -
 src/OpenFOAM/db/IOstreams/Sstreams/OSstream.C |   7 --
 src/OpenFOAM/db/IOstreams/Tstreams/ITstream.H |   6 -
 .../db/IOstreams/memory/ISpanStream.H         |   8 --
 .../db/IOstreams/memory/memoryStreamBuffer.H  |  16 +--
 .../formattingEntry/formattingEntry.C         |   6 +-
 .../primitives/strings/lists/SubStrings.H     |   4 -
 25 files changed, 82 insertions(+), 156 deletions(-)
 rename applications/test/Hashing2/{Test-Hashing2.C => Test-Hashing2.cxx} (99%)
 rename applications/test/ICharStream1/{Test-ICharStream1.C => Test-ICharStream1.cxx} (96%)
 rename applications/test/ListRead1/{Test-ListRead1.C => Test-ListRead1.cxx} (99%)
 rename applications/test/OCharStream1/{Test-OCharStream1.C => Test-OCharStream1.cxx} (96%)
 rename applications/test/SpanStream1/{Test-SpanStream1.C => Test-SpanStream1.cxx} (96%)
 rename applications/test/dictionaryTokens/{Test-dictionaryTokens.C => Test-dictionaryTokens.cxx} (100%)
 rename applications/test/dictionaryTokens/{dictionaryTokens.C => dictionaryTokens.cxx} (100%)
 rename applications/test/string_view1/{Test-string_view1.C => Test-string_view1.cxx} (92%)
 rename applications/test/tokenize/{Test-tokenize.C => Test-tokenize.cxx} (100%)

diff --git a/applications/test/Hashing2/Make/files b/applications/test/Hashing2/Make/files
index 86776cfe25..911922f768 100644
--- a/applications/test/Hashing2/Make/files
+++ b/applications/test/Hashing2/Make/files
@@ -1,3 +1,3 @@
-Test-Hashing2.C
+Test-Hashing2.cxx
 
 EXE = $(FOAM_USER_APPBIN)/Test-Hashing2
diff --git a/applications/test/Hashing2/Test-Hashing2.C b/applications/test/Hashing2/Test-Hashing2.cxx
similarity index 99%
rename from applications/test/Hashing2/Test-Hashing2.C
rename to applications/test/Hashing2/Test-Hashing2.cxx
index 244afbbcc5..4fc27a566a 100644
--- a/applications/test/Hashing2/Test-Hashing2.C
+++ b/applications/test/Hashing2/Test-Hashing2.cxx
@@ -274,9 +274,7 @@ int main(int argc, char *argv[])
         Info<< nl << "No " << is.name() << " file found ..." << nl;
     }
 
-    token tok;
-
-    while (is.good() && is.read(tok) && tok.good())
+    for (token tok; tok.read(is); /*nil*/)
     {
         const word listType(tok.wordToken());
 
diff --git a/applications/test/ICharStream1/Make/files b/applications/test/ICharStream1/Make/files
index e7f106f94a..9cab0c781d 100644
--- a/applications/test/ICharStream1/Make/files
+++ b/applications/test/ICharStream1/Make/files
@@ -1,3 +1,3 @@
-Test-ICharStream1.C
+Test-ICharStream1.cxx
 
 EXE = $(FOAM_USER_APPBIN)/Test-ICharStream1
diff --git a/applications/test/ICharStream1/Test-ICharStream1.C b/applications/test/ICharStream1/Test-ICharStream1.cxx
similarity index 96%
rename from applications/test/ICharStream1/Test-ICharStream1.C
rename to applications/test/ICharStream1/Test-ICharStream1.cxx
index cf36c3cddd..97853911c7 100644
--- a/applications/test/ICharStream1/Test-ICharStream1.C
+++ b/applications/test/ICharStream1/Test-ICharStream1.cxx
@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2017-2023 OpenCFD Ltd.
+    Copyright (C) 2017-2025 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -83,12 +83,10 @@ Ostream& printView(Ostream& os, const char* first, const char* last)
 }
 
 
-#if __cplusplus >= 201703L
 Ostream& printView(Ostream& os, std::string_view s)
 {
     return printView(os, s.begin(), s.end());
 }
-#endif
 
 
 Ostream& printView(Ostream& os, stdFoam::span<char> s)
@@ -138,17 +136,10 @@ void printInfo(const List<char>& buf)
 void printTokens(Istream& is)
 {
     label count = 0;
-    token t;
-    while (is.good())
+    for (token tok; tok.read(is); ++count)
     {
-        is >> t;
-        if (t.good())
-        {
-            ++count;
-            Info<<"token: " << t << endl;
-        }
+        Info<< "token: " << tok << nl;
     }
-
     Info<< count << " tokens" << endl;
 }
 
diff --git a/applications/test/ITstream/Test-ITstream.cxx b/applications/test/ITstream/Test-ITstream.cxx
index 6aa034b04a..17592aed89 100644
--- a/applications/test/ITstream/Test-ITstream.cxx
+++ b/applications/test/ITstream/Test-ITstream.cxx
@@ -73,14 +73,13 @@ Ostream& toString(Ostream& os, const List<char>& list)
 
 void printTokens(Istream& is)
 {
-    label count = 0;
-
     Info<< "stream tokens:" << endl;
+
+    label count = 0;
     for (token tok; tok.read(is); ++count)
     {
-        Info<< "  : " << tok << endl;
+        Info<< "  : " << tok << nl;
     }
-
     Info<< count << " tokens" << endl;
 }
 
diff --git a/applications/test/ListRead1/Test-ListRead1.C b/applications/test/ListRead1/Test-ListRead1.cxx
similarity index 99%
rename from applications/test/ListRead1/Test-ListRead1.C
rename to applications/test/ListRead1/Test-ListRead1.cxx
index aac211e2da..db9926a58e 100644
--- a/applications/test/ListRead1/Test-ListRead1.C
+++ b/applications/test/ListRead1/Test-ListRead1.cxx
@@ -85,7 +85,7 @@ bool readBracketList(List<T>& list, Istream& is)
         // constexpr label chunkSize = 128;
         typedef std::unique_ptr<List<T>> chunkType;
 
-        is >> tok;
+        tok.read(is);
         is.fatalCheck(FUNCTION_NAME);
 
         if (tok.isPunctuation(token::END_LIST))
@@ -149,7 +149,7 @@ bool readBracketList(List<T>& list, Istream& is)
                 "reading entry"
             );
 
-            is >> tok;
+            tok.read(is);
             is.fatalCheck(FUNCTION_NAME);
         }
 
diff --git a/applications/test/OCharStream1/Make/files b/applications/test/OCharStream1/Make/files
index 5613de82c1..9bb340983c 100644
--- a/applications/test/OCharStream1/Make/files
+++ b/applications/test/OCharStream1/Make/files
@@ -1,3 +1,3 @@
-Test-OCharStream1.C
+Test-OCharStream1.cxx
 
 EXE = $(FOAM_USER_APPBIN)/Test-OCharStream1
diff --git a/applications/test/OCharStream1/Test-OCharStream1.C b/applications/test/OCharStream1/Test-OCharStream1.cxx
similarity index 96%
rename from applications/test/OCharStream1/Test-OCharStream1.C
rename to applications/test/OCharStream1/Test-OCharStream1.cxx
index f4039f231b..7499b9c04a 100644
--- a/applications/test/OCharStream1/Test-OCharStream1.C
+++ b/applications/test/OCharStream1/Test-OCharStream1.cxx
@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2017-2023 OpenCFD Ltd.
+    Copyright (C) 2017-2025 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -83,12 +83,10 @@ Ostream& printView(Ostream& os, const char* first, const char* last)
 }
 
 
-#if __cplusplus >= 201703L
 Ostream& printView(Ostream& os, std::string_view s)
 {
     return printView(os, s.begin(), s.end());
 }
-#endif
 
 
 Ostream& printView(Ostream& os, stdFoam::span<char> s)
@@ -129,17 +127,10 @@ void printInfo(const BufType& buf)
 void printTokens(Istream& is)
 {
     label count = 0;
-    token t;
-    while (is.good())
+    for (token tok; tok.read(is); ++count)
     {
-        is >> t;
-        if (t.good())
-        {
-            ++count;
-            Info<<"token: " << t << endl;
-        }
+        Info<< "token: " << tok << nl;
     }
-
     Info<< count << " tokens" << endl;
 }
 
diff --git a/applications/test/SpanStream1/Make/files b/applications/test/SpanStream1/Make/files
index 4af7ed78cd..8ec12e8b23 100644
--- a/applications/test/SpanStream1/Make/files
+++ b/applications/test/SpanStream1/Make/files
@@ -1,3 +1,3 @@
-Test-SpanStream1.C
+Test-SpanStream1.cxx
 
 EXE = $(FOAM_USER_APPBIN)/Test-SpanStream1
diff --git a/applications/test/SpanStream1/Test-SpanStream1.C b/applications/test/SpanStream1/Test-SpanStream1.cxx
similarity index 96%
rename from applications/test/SpanStream1/Test-SpanStream1.C
rename to applications/test/SpanStream1/Test-SpanStream1.cxx
index 92fb58daa0..6e6e988b14 100644
--- a/applications/test/SpanStream1/Test-SpanStream1.C
+++ b/applications/test/SpanStream1/Test-SpanStream1.cxx
@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2017-2023 OpenCFD Ltd.
+    Copyright (C) 2017-2025 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -85,12 +85,10 @@ Ostream& printView(Ostream& os, const char* first, const char* last)
 }
 
 
-#if __cplusplus >= 201703L
 Ostream& printView(Ostream& os, std::string_view s)
 {
     return printView(os, s.begin(), s.end());
 }
-#endif
 
 
 Ostream& printView(Ostream& os, stdFoam::span<char> s)
@@ -145,17 +143,10 @@ void printInfo(const UList<char>& buf)
 void printTokens(Istream& is)
 {
     label count = 0;
-    token t;
-    while (is.good())
+    for (token tok; tok.read(is); ++count)
     {
-        is >> t;
-        if (t.good())
-        {
-            ++count;
-            Info<<"token: " << t << endl;
-        }
+        Info<< "token: " << tok << nl;
     }
-
     Info<< count << " tokens" << endl;
 }
 
diff --git a/applications/test/dictionaryTokens/Make/files b/applications/test/dictionaryTokens/Make/files
index 413023a014..501c165765 100644
--- a/applications/test/dictionaryTokens/Make/files
+++ b/applications/test/dictionaryTokens/Make/files
@@ -1,4 +1,4 @@
-Test-dictionaryTokens.C
-dictionaryTokens.C
+Test-dictionaryTokens.cxx
+dictionaryTokens.cxx
 
 EXE = $(FOAM_USER_APPBIN)/Test-dictionaryTokens
diff --git a/applications/test/dictionaryTokens/Test-dictionaryTokens.C b/applications/test/dictionaryTokens/Test-dictionaryTokens.cxx
similarity index 100%
rename from applications/test/dictionaryTokens/Test-dictionaryTokens.C
rename to applications/test/dictionaryTokens/Test-dictionaryTokens.cxx
diff --git a/applications/test/dictionaryTokens/dictionaryTokens.C b/applications/test/dictionaryTokens/dictionaryTokens.cxx
similarity index 100%
rename from applications/test/dictionaryTokens/dictionaryTokens.C
rename to applications/test/dictionaryTokens/dictionaryTokens.cxx
diff --git a/applications/test/string_view1/Make/files b/applications/test/string_view1/Make/files
index 4d92aada22..c11f6fa346 100644
--- a/applications/test/string_view1/Make/files
+++ b/applications/test/string_view1/Make/files
@@ -1,3 +1,3 @@
-Test-string_view1.C
+Test-string_view1.cxx
 
 EXE = $(FOAM_USER_APPBIN)/Test-string_view1
diff --git a/applications/test/string_view1/Test-string_view1.C b/applications/test/string_view1/Test-string_view1.cxx
similarity index 92%
rename from applications/test/string_view1/Test-string_view1.C
rename to applications/test/string_view1/Test-string_view1.cxx
index 155e364165..bbb24dc8fe 100644
--- a/applications/test/string_view1/Test-string_view1.C
+++ b/applications/test/string_view1/Test-string_view1.cxx
@@ -40,11 +40,6 @@ using namespace Foam;
 int main(int argc, char *argv[])
 {
     Info<< "Compiled with C++ " << __cplusplus;
-    #if __cplusplus >= 201703L
-    Info<< " - has std::string_view" << nl << nl;
-    #else
-    Info<< " - NO std::string_view" << nl << nl;
-    #endif
 
     // basics
     {
@@ -63,9 +58,7 @@ int main(int argc, char *argv[])
                 << "input: <" << cstr << '>'
                 << " type: " << typeid(cstr).name() << " len:" << len << nl;
 
-            #if __cplusplus >= 201703L
             Info<< "    view: " << std::string_view(cstr) << nl;
-            #endif
 
             Info<< "    span: "
                 << stdFoam::span<const char>(cstr, len) << nl;
diff --git a/applications/test/token/Test-token.cxx b/applications/test/token/Test-token.cxx
index 52b2eb7571..7fda54b642 100644
--- a/applications/test/token/Test-token.cxx
+++ b/applications/test/token/Test-token.cxx
@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2017-2024 OpenCFD Ltd.
+    Copyright (C) 2017-2025 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -134,50 +134,51 @@ int main(int argc, char *argv[])
         Info<< "resized: "
             << ctok1.info() << nl << ctok1 << endl;
 
+        // Using isA<> on compoundToken()
+        if
+        (
+            const auto* listptr
+          = ctok1.compoundToken().isA<scalarList>()
+        )
         {
-            // Using isA<> on compoundToken()
-            const auto* listptr = ctok1.compoundToken().isA<scalarList>();
-            if (listptr)
-            {
-                // sneaky, SubField bypasses const!
-                scalarField::subField fld(*listptr);
-                fld *= 5;
+            // sneaky, SubField bypasses const!
+            scalarField::subField fld(*listptr);
+            fld *= 5;
 
-                Info<< "multiplied List<scalar>: "
-                    << ctok1.info() << nl << ctok1 << endl;
-            }
+            Info<< "multiplied List<scalar>: "
+                << ctok1.info() << nl << ctok1 << endl;
         }
 
+        // Using isCompound<...> - combined check
+        if
+        (
+            const auto* listptr
+          = ctok1.isCompound<scalarList>()
+        )
         {
-            // Using isCompound<...> - combined check
+            scalarField::subField fld(*listptr);
+            fld /= 2;
 
-            const auto* listptr = ctok1.isCompound<scalarList>();
-            if (listptr)
-            {
-                scalarField::subField fld(*listptr);
-                fld /= 2;
-
-                Info<< "divided List<scalar>: "
-                    << ctok1.info() << nl << ctok1 << endl;
-            }
+            Info<< "divided List<scalar>: "
+                << ctok1.info() << nl << ctok1 << endl;
         }
 
+        // Using isCompound<...> - combined check
+        if
+        (
+            const auto* listptr
+          = ctok1.isCompound<labelList>()
+        )
         {
-            // Using isCompound<...> - combined check
+            labelField::subField fld(*listptr);
+            fld /= 2;
 
-            const auto* listptr = ctok1.isCompound<labelList>();
-            if (listptr)
-            {
-                labelField::subField fld(*listptr);
-                fld /= 2;
-
-                Info<< "divided List<label>: "
-                    << ctok1.info() << nl << ctok1 << endl;
-            }
-            else
-            {
-                Info<< "compound is not List<label>" << nl;
-            }
+            Info<< "divided List<label>: "
+                << ctok1.info() << nl << ctok1 << endl;
+        }
+        else
+        {
+            Info<< "compound is not List<label>" << nl;
         }
 
         Info<< "Before fill_zero: " << ctok1 << endl;
@@ -248,13 +249,14 @@ int main(int argc, char *argv[])
 
         token tok;
 
+        if (auto v = obuf.view(); !v.empty())
         {
-            auto v = obuf.view();
-            if (!v.empty())
-            {
-                tok = string(v.data(), v.size());
-                tok.setType(token::tokenType::CHAR_DATA);
-            }
+            tok = string(v.data(), v.size());
+            tok.setType(token::tokenType::CHAR_DATA);
+        }
+        else
+        {
+            tok = token();
         }
 
         Info<< "tok: " << tok.name() << nl << nl;
@@ -274,13 +276,14 @@ int main(int argc, char *argv[])
 
         obuf.endBlock();
 
+        if (auto v = obuf.view(); !v.empty())
         {
-            auto v = obuf.view();
-            if (!v.empty())
-            {
-                tok = string(v.data(), v.size());
-                tok.setType(token::tokenType::CHAR_DATA);
-            }
+            tok = string(v.data(), v.size());
+            tok.setType(token::tokenType::CHAR_DATA);
+        }
+        else
+        {
+            tok = token();
         }
 
         // Output like xml:
@@ -349,10 +352,11 @@ int main(int argc, char *argv[])
         {
             typedef List<scalar> ListType;
 
-            auto* inputDataPtr =
-                const_cast<ListType*>(entry0.stream().findCompound<ListType>());
-
-            if (inputDataPtr)
+            if
+            (
+                auto* inputDataPtr
+              = const_cast<ListType*>(entry0.stream().findCompound<ListType>())
+            )
             {
                 Info<< "found input data" << nl;
                 Info<< entry0 << nl;
diff --git a/applications/test/tokenize/Make/files b/applications/test/tokenize/Make/files
index b4ce91199e..673d263255 100644
--- a/applications/test/tokenize/Make/files
+++ b/applications/test/tokenize/Make/files
@@ -1,3 +1,3 @@
-Test-tokenize.C
+Test-tokenize.cxx
 
 EXE = $(FOAM_USER_APPBIN)/Test-tokenize
diff --git a/applications/test/tokenize/Test-tokenize.C b/applications/test/tokenize/Test-tokenize.cxx
similarity index 100%
rename from applications/test/tokenize/Test-tokenize.C
rename to applications/test/tokenize/Test-tokenize.cxx
diff --git a/src/OpenFOAM/db/IOstreams/IOstreams/Ostream.H b/src/OpenFOAM/db/IOstreams/IOstreams/Ostream.H
index a8ec427a6a..f2ab0772b8 100644
--- a/src/OpenFOAM/db/IOstreams/IOstreams/Ostream.H
+++ b/src/OpenFOAM/db/IOstreams/IOstreams/Ostream.H
@@ -327,7 +327,6 @@ public:
 
 // * * * * * * * * * * * * * * * Global Operators  * * * * * * * * * * * * * //
 
-#if __cplusplus >= 201703L
 //- Write operator for std::string_view
 inline Ostream& operator<<(Ostream& os, std::string_view s)
 {
@@ -335,7 +334,6 @@ inline Ostream& operator<<(Ostream& os, std::string_view s)
     os.check("Foam::operator<<(Ostream&, std::string_view)");
     return os;
 }
-#endif
 
 //- Write operator for character span. Output like string data
 inline Ostream& operator<<(Ostream& os, stdFoam::span<char> s)
diff --git a/src/OpenFOAM/db/IOstreams/Sstreams/OSstream.C b/src/OpenFOAM/db/IOstreams/Sstreams/OSstream.C
index f08ff4cd2d..96267e4cdf 100644
--- a/src/OpenFOAM/db/IOstreams/Sstreams/OSstream.C
+++ b/src/OpenFOAM/db/IOstreams/Sstreams/OSstream.C
@@ -117,14 +117,7 @@ Foam::Ostream& Foam::OSstream::writeQuoted
 
     if (!quoted)
     {
-        #if __cplusplus >= 201703L
         os_ << std::string_view(str, len);
-        #else
-        for (const char* iter = str; iter != last; ++iter)
-        {
-            os_ << *iter;
-        }
-        #endif
         syncState();
 
         // Unquoted, only advance line number on newline
diff --git a/src/OpenFOAM/db/IOstreams/Tstreams/ITstream.H b/src/OpenFOAM/db/IOstreams/Tstreams/ITstream.H
index 7d3157a3b6..398a12238f 100644
--- a/src/OpenFOAM/db/IOstreams/Tstreams/ITstream.H
+++ b/src/OpenFOAM/db/IOstreams/Tstreams/ITstream.H
@@ -165,11 +165,7 @@ public:
         //  Uses static parse function internally.
         explicit ITstream
         (
-            #if __cplusplus >= 201703L
             std::string_view s,
-            #else
-            const std::string& s,
-            #endif
             IOstreamOption streamOpt = IOstreamOption(),
             const string& name = "input"
         )
@@ -281,7 +277,6 @@ public:
             return parse_chars(input, strlen(input), streamOpt);
         }
 
-        #if __cplusplus >= 201703L
         //- Create token list by parsing the input character sequence
         //- until no good tokens remain.
         static tokenList parse
@@ -292,7 +287,6 @@ public:
         {
             return parse_chars(s.data(), s.size(), streamOpt);
         }
-        #endif
 
         //- Create token list by parsing the input character sequence
         //- until no good tokens remain.
diff --git a/src/OpenFOAM/db/IOstreams/memory/ISpanStream.H b/src/OpenFOAM/db/IOstreams/memory/ISpanStream.H
index 3d0b7e5738..f8b2adba15 100644
--- a/src/OpenFOAM/db/IOstreams/memory/ISpanStream.H
+++ b/src/OpenFOAM/db/IOstreams/memory/ISpanStream.H
@@ -116,14 +116,12 @@ public:
             stream_type(static_cast<buffer_type*>(this))
         {}
 
-        #if __cplusplus >= 201703L
         //- Construct (shallow copy) from std::string_view content
         explicit ispanstream(std::string_view s)
         :
             buffer_type(const_cast<char*>(s.data()), s.size()),
             stream_type(static_cast<buffer_type*>(this))
         {}
-        #endif
 
         //- Construct (shallow copy) from span character content
         explicit ispanstream(stdFoam::span<char> s)
@@ -215,14 +213,12 @@ public:
             stream_type::clear();  // Clear old errors
         }
 
-        #if __cplusplus >= 201703L
         //- Reset the get buffer area to use the data from a string_view
         void reset(std::string_view s)
         {
             buffer_type::resetg(const_cast<char*>(s.data()), s.size());
             stream_type::clear();  // Clear old errors
         }
-        #endif
 
         //- Some information about the input buffer position/capacity
         void debug_info(Ostream& os) const
@@ -292,7 +288,6 @@ public:
             ISpanStream(s.data(), s.size(), streamOpt)
         {}
 
-        #if __cplusplus >= 201703L
         //- Use data area from string_view content
         explicit ISpanStream
         (
@@ -302,7 +297,6 @@ public:
         :
             ISpanStream(s.data(), s.size(), streamOpt)
         {}
-        #endif
 
         //- Construct using data area from a List and its inherent storage size
         //  Uses addressed size, thus no special treatment for a DynamicList
@@ -384,14 +378,12 @@ public:
             syncState();
         }
 
-        #if __cplusplus >= 201703L
         //- Reset input area to use data from a std::string_view
         void reset(std::string_view s)
         {
             stream_.reset(s.data(), s.size());
             syncState();
         }
-        #endif
 
         //- Reset input area to use data from span character content
         void reset(stdFoam::span<char> s)
diff --git a/src/OpenFOAM/db/IOstreams/memory/memoryStreamBuffer.H b/src/OpenFOAM/db/IOstreams/memory/memoryStreamBuffer.H
index 5d3638c5b1..dec0c30999 100644
--- a/src/OpenFOAM/db/IOstreams/memory/memoryStreamBuffer.H
+++ b/src/OpenFOAM/db/IOstreams/memory/memoryStreamBuffer.H
@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2016-2023 OpenCFD Ltd.
+    Copyright (C) 2016-2025 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -213,17 +213,10 @@ public:
         //- The span size (number of input characters)
         std::streamsize size_bytes() const { return (egptr() - eback()); }
 
-        #if __cplusplus >= 201703L
         std::string_view view() const
         {
             return std::string_view(data_bytes(), size_bytes());
         }
-        #else
-        stdFoam::span<const char> view() const
-        {
-            return stdFoam::span<const char>(data_bytes(), size_bytes());
-        }
-        #endif
 
         //- Some information about the input buffer position/capacity
         void info(Ostream& os) const
@@ -403,17 +396,10 @@ public:
         //- The span size (size of output buffer)
         std::streamsize size_bytes() const { return (pptr() - pbase()); }
 
-        #if __cplusplus >= 201703L
         std::string_view view() const
         {
             return std::string_view(data_bytes(), size_bytes());
         }
-        #else
-        stdFoam::span<const char> view() const
-        {
-            return stdFoam::span<const char>(data_bytes(), size_bytes());
-        }
-        #endif
 
         //- Some information about the output buffer position/capacity
         void info(Ostream& os) const
diff --git a/src/OpenFOAM/db/dictionary/formattingEntry/formattingEntry.C b/src/OpenFOAM/db/dictionary/formattingEntry/formattingEntry.C
index a3f80dd28f..aca3ffe9c3 100644
--- a/src/OpenFOAM/db/dictionary/formattingEntry/formattingEntry.C
+++ b/src/OpenFOAM/db/dictionary/formattingEntry/formattingEntry.C
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2023 Sergey Lesnik
-    Copyright (C) 2023-2024 OpenCFD Ltd.
+    Copyright (C) 2023-2025 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -37,7 +37,7 @@ namespace Foam
 // Write tokens without keyword, suppress/ignore bad tokens.
 // Mostly like primitiveEntry::write(os, true);
 
-static void writeTokens(Ostream& os, const tokenList& toks)
+static void writeTokens(Ostream& os, const UList<token>& toks)
 {
     bool started = false;  // Separate from previous token?
 
@@ -110,7 +110,7 @@ Foam::formattingEntry::formattingEntry
     primitiveEntry
     (
         key,
-        token(token::tokenType::CHAR_DATA, std::move(content))
+        token(token::tokenType::CHAR_DATA, content)
     )
 {}
 
diff --git a/src/OpenFOAM/primitives/strings/lists/SubStrings.H b/src/OpenFOAM/primitives/strings/lists/SubStrings.H
index 78f1496323..eb98de37ee 100644
--- a/src/OpenFOAM/primitives/strings/lists/SubStrings.H
+++ b/src/OpenFOAM/primitives/strings/lists/SubStrings.H
@@ -57,7 +57,6 @@ public:
 
     // Static Functions
 
-        #if __cplusplus >= 201703L
         //- Return match as a string_view
         static std::string_view view(const std::ssub_match& m)
         {
@@ -74,7 +73,6 @@ public:
             );
             #endif
         }
-        #endif  /* __cplusplus >= 201703L */
 
 
     // Member Functions
@@ -105,13 +103,11 @@ public:
             return (*this)[pos].str();
         }
 
-        #if __cplusplus >= 201703L
         //- Return element at pos as a string_view
         std::string_view view(size_t pos) const
         {
             return view((*this)[pos]);
         }
-        #endif  /* __cplusplus >= 201703L */
 
         //- Append sub-string defined by begin/end iterators
         void append