From bbde236be57e876de95b1eefed6d46241b609962 Mon Sep 17 00:00:00 2001
From: Mark Olesen <Mark.Olesen@esi-group.com>
Date: Fri, 17 May 2024 10:12:41 +0200
Subject: [PATCH] ENH: simpler internal handling of stderr in message streams

- delay construction of message buffer

- OStringStream count() method to test if anything has been streamed

STYLE: explicit use of std::ios_base in IOstreams

- document the return information of set flag methods
---
 applications/test/OCountStream/Make/files     |   2 +-
 ...t-OCountStream.C => Test-OCountStream.cxx} |   6 +-
 src/OpenFOAM/db/IOstreams/IOstreams/IOmanip.H |   4 +-
 .../db/IOstreams/IOstreams/IOstream.C         |  12 +--
 .../db/IOstreams/IOstreams/IOstream.H         |  24 ++---
 .../db/IOstreams/Pstreams/UIPstream.H         |  14 +--
 .../db/IOstreams/Pstreams/UOPstream.H         |  25 +++--
 src/OpenFOAM/db/IOstreams/Sstreams/ISstream.H |  11 +-
 src/OpenFOAM/db/IOstreams/Sstreams/OSstream.H |  11 +-
 .../db/IOstreams/StringStreams/StringStream.H |   3 +
 src/OpenFOAM/db/IOstreams/Tstreams/ITstream.H |  14 +--
 src/OpenFOAM/db/IOstreams/Tstreams/OTstream.H |  14 +--
 .../db/IOstreams/dummy/dummyISstream.H        |  14 +--
 src/OpenFOAM/db/error/IOerror.C               |  13 +--
 src/OpenFOAM/db/error/error.C                 |  40 ++++---
 src/OpenFOAM/db/error/error.H                 |  16 ++-
 src/OpenFOAM/db/error/messageStream.C         | 102 +++++++++++-------
 src/OpenFOAM/db/error/messageStream.H         |  56 +++++++---
 .../adjoint/objectives/objective/objective.C  |   5 +-
 src/sampling/probes/probes.C                  |   2 +-
 20 files changed, 238 insertions(+), 150 deletions(-)
 rename applications/test/OCountStream/{Test-OCountStream.C => Test-OCountStream.cxx} (96%)

diff --git a/applications/test/OCountStream/Make/files b/applications/test/OCountStream/Make/files
index 87df932eea..504d53099d 100644
--- a/applications/test/OCountStream/Make/files
+++ b/applications/test/OCountStream/Make/files
@@ -1,3 +1,3 @@
-Test-OCountStream.C
+Test-OCountStream.cxx
 
 EXE = $(FOAM_USER_APPBIN)/Test-OCountStream
diff --git a/applications/test/OCountStream/Test-OCountStream.C b/applications/test/OCountStream/Test-OCountStream.cxx
similarity index 96%
rename from applications/test/OCountStream/Test-OCountStream.C
rename to applications/test/OCountStream/Test-OCountStream.cxx
index 85ffab4e0c..1d073efe43 100644
--- a/applications/test/OCountStream/Test-OCountStream.C
+++ b/applications/test/OCountStream/Test-OCountStream.cxx
@@ -65,11 +65,11 @@ int main(int argc, char *argv[])
 
     OCountStream cnt;
     OCharStream cstr;
-    OStringStream str;
+    OStringStream sstr;
     ocountstream plain;
 
     generateOutput(cstr);
-    generateOutput(str);
+    generateOutput(sstr);
     generateOutput(cnt);
     generateOutput(plain);
 
@@ -77,7 +77,7 @@ int main(int argc, char *argv[])
 
     Info<< "counter state: " << (cnt.stdStream().rdstate()) << nl
         << "via char-stream: " << label(cstr.view().size()) << " chars" << nl
-        << "via string-stream: " << str.str().size() << " chars" << nl
+        << "via string-stream: " << label(sstr.count()) << " chars" << nl
         << "via ocountstream: " << plain.count() << " chars" << endl;
 
     fileName outputName;
diff --git a/src/OpenFOAM/db/IOstreams/IOstreams/IOmanip.H b/src/OpenFOAM/db/IOstreams/IOstreams/IOmanip.H
index 4df38b3276..08456800d5 100644
--- a/src/OpenFOAM/db/IOstreams/IOstreams/IOmanip.H
+++ b/src/OpenFOAM/db/IOstreams/IOstreams/IOmanip.H
@@ -166,9 +166,9 @@ inline Ostream& operator<<(Ostream& os, const Omanip<T>& m)
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
-inline Smanip<ios_base::fmtflags> setf(const ios_base::fmtflags flags)
+inline Smanip<std::ios_base::fmtflags> setf(std::ios_base::fmtflags flags)
 {
-    return Smanip<ios_base::fmtflags>(&IOstream::setf, flags);
+    return Smanip<std::ios_base::fmtflags>(&IOstream::setf, flags);
 }
 
 
diff --git a/src/OpenFOAM/db/IOstreams/IOstreams/IOstream.C b/src/OpenFOAM/db/IOstreams/IOstreams/IOstream.C
index a627e382bf..889b2e19f6 100644
--- a/src/OpenFOAM/db/IOstreams/IOstreams/IOstream.C
+++ b/src/OpenFOAM/db/IOstreams/IOstreams/IOstream.C
@@ -114,23 +114,19 @@ void Foam::IOstream::print(Ostream& os, const int streamState) const
 {
     if (streamState == std::ios_base::goodbit)
     {
-        os  << "ios_base::goodbit set : the last operation on stream succeeded"
-            << endl;
+        os  << "goodbit set : the last operation on stream succeeded" << endl;
     }
     else if (streamState & std::ios_base::badbit)
     {
-        os  << "ios_base::badbit set : characters possibly lost"
-            << endl;
+        os  << "badbit set : characters possibly lost" << endl;
     }
     else if (streamState & std::ios_base::failbit)
     {
-        os  << "ios_base::failbit set : some type of formatting error"
-            << endl;
+        os  << "failbit set : some type of formatting error" << endl;
     }
     else if (streamState & std::ios_base::eofbit)
     {
-        os  << "ios_base::eofbit set : at end of stream"
-            << endl;
+        os  << "eofbit set : at end of stream" << endl;
     }
 }
 
diff --git a/src/OpenFOAM/db/IOstreams/IOstreams/IOstream.H b/src/OpenFOAM/db/IOstreams/IOstreams/IOstream.H
index 01546afc1b..b67807efcd 100644
--- a/src/OpenFOAM/db/IOstreams/IOstreams/IOstream.H
+++ b/src/OpenFOAM/db/IOstreams/IOstreams/IOstream.H
@@ -339,9 +339,6 @@ public:
             return old;
         }
 
-        //- Return flags of stream
-        virtual ios_base::fmtflags flags() const = 0;
-
         //- Return the default precision
         static unsigned int defaultPrecision() noexcept
         {
@@ -387,27 +384,30 @@ public:
             ioState_ |= std::ios_base::badbit;
         }
 
-        //- Set flags of stream
-        virtual ios_base::fmtflags flags(const ios_base::fmtflags f) = 0;
+        //- Return current stream flags
+        virtual std::ios_base::fmtflags flags() const = 0;
 
-        //- Set flags of stream
-        ios_base::fmtflags setf(const ios_base::fmtflags f)
+        //- Set stream flags, return old stream flags
+        virtual std::ios_base::fmtflags flags(std::ios_base::fmtflags) = 0;
+
+        //- Set stream flag(s), return old stream flags
+        std::ios_base::fmtflags setf(std::ios_base::fmtflags f)
         {
             return flags(flags() | f);
         }
 
-        //- Set flags of given field of stream
-        ios_base::fmtflags setf
+        //- Set stream flag(s) with mask, return old stream flags
+        std::ios_base::fmtflags setf
         (
-            const ios_base::fmtflags f,
-            const ios_base::fmtflags mask
+            const std::ios_base::fmtflags f,
+            const std::ios_base::fmtflags mask
         )
         {
             return flags((flags() & ~mask) | (f & mask));
         }
 
         //- Unset flags of stream
-        void unsetf(const ios_base::fmtflags f)
+        void unsetf(std::ios_base::fmtflags f)
         {
             flags(flags() & ~f);
         }
diff --git a/src/OpenFOAM/db/IOstreams/Pstreams/UIPstream.H b/src/OpenFOAM/db/IOstreams/Pstreams/UIPstream.H
index 138dc465a8..eb2deb9a87 100644
--- a/src/OpenFOAM/db/IOstreams/Pstreams/UIPstream.H
+++ b/src/OpenFOAM/db/IOstreams/Pstreams/UIPstream.H
@@ -151,16 +151,18 @@ public:
 
     // Stream State Functions
 
-        //- Return stream flags
-        virtual ios_base::fmtflags flags() const override
+        //- Return current stream flags.
+        //- Dummy for parallel stream, returns 0.
+        virtual std::ios_base::fmtflags flags() const override
         {
-            return ios_base::fmtflags(0);
+            return std::ios_base::fmtflags(0);
         }
 
-        //- Set flags of stream flags
-        virtual ios_base::fmtflags flags(const ios_base::fmtflags) override
+        //- Set stream flags, return old stream flags.
+        //- Dummy for parallel stream, returns 0.
+        virtual std::ios_base::fmtflags flags(std::ios_base::fmtflags) override
         {
-            return ios_base::fmtflags(0);
+            return std::ios_base::fmtflags(0);
         }
 
 
diff --git a/src/OpenFOAM/db/IOstreams/Pstreams/UOPstream.H b/src/OpenFOAM/db/IOstreams/Pstreams/UOPstream.H
index 8519e03f81..e96a05d875 100644
--- a/src/OpenFOAM/db/IOstreams/Pstreams/UOPstream.H
+++ b/src/OpenFOAM/db/IOstreams/Pstreams/UOPstream.H
@@ -144,12 +144,20 @@ public:
 
     // Member Functions
 
-    // Inquiry
+    // Stream State Functions
 
-        //- Return flags of output stream
-        virtual ios_base::fmtflags flags() const override
+        //- Return current stream flags.
+        //- Dummy for parallel stream, returns 0.
+        virtual std::ios_base::fmtflags flags() const override
         {
-            return ios_base::fmtflags(0);
+            return std::ios_base::fmtflags(0);
+        }
+
+        //- Set stream flags, return old stream flags.
+        //- Dummy for parallel stream, returns 0.
+        virtual std::ios_base::fmtflags flags(std::ios_base::fmtflags) override
+        {
+            return std::ios_base::fmtflags(0);
         }
 
 
@@ -281,15 +289,6 @@ public:
         virtual void rewind();
 
 
-    // Edit
-
-        //- Set flags of stream
-        virtual ios_base::fmtflags flags(const ios_base::fmtflags) override
-        {
-            return ios_base::fmtflags(0);
-        }
-
-
     // Print
 
         //- Print stream description to Ostream
diff --git a/src/OpenFOAM/db/IOstreams/Sstreams/ISstream.H b/src/OpenFOAM/db/IOstreams/Sstreams/ISstream.H
index cb09f060fe..223784367a 100644
--- a/src/OpenFOAM/db/IOstreams/Sstreams/ISstream.H
+++ b/src/OpenFOAM/db/IOstreams/Sstreams/ISstream.H
@@ -147,14 +147,17 @@ public:
 
     // Stream State
 
-        //- Return flags of output stream
-        virtual ios_base::fmtflags flags() const override
+        //- Return current stream flags
+        virtual std::ios_base::fmtflags flags() const override
         {
             return is_.flags();
         }
 
-        //- Set stream flags
-        virtual ios_base::fmtflags flags(const ios_base::fmtflags f) override
+        //- Set stream flags, return old stream flags
+        virtual std::ios_base::fmtflags flags
+        (
+            std::ios_base::fmtflags f
+        ) override
         {
             return is_.flags(f);
         }
diff --git a/src/OpenFOAM/db/IOstreams/Sstreams/OSstream.H b/src/OpenFOAM/db/IOstreams/Sstreams/OSstream.H
index dd76e3d8b0..3344fc7739 100644
--- a/src/OpenFOAM/db/IOstreams/Sstreams/OSstream.H
+++ b/src/OpenFOAM/db/IOstreams/Sstreams/OSstream.H
@@ -138,14 +138,17 @@ public:
 
     // Stream State
 
-        //- Get stream flags
-        virtual ios_base::fmtflags flags() const override
+        //- Get current stream flags
+        virtual std::ios_base::fmtflags flags() const override
         {
             return os_.flags();
         }
 
-        //- Set stream flags
-        virtual ios_base::fmtflags flags(const ios_base::fmtflags f) override
+        //- Set stream flags, return old stream flags
+        virtual std::ios_base::fmtflags flags
+        (
+            std::ios_base::fmtflags f
+        ) override
         {
             return os_.flags(f);
         }
diff --git a/src/OpenFOAM/db/IOstreams/StringStreams/StringStream.H b/src/OpenFOAM/db/IOstreams/StringStreams/StringStream.H
index 0950df267a..63089e40e9 100644
--- a/src/OpenFOAM/db/IOstreams/StringStreams/StringStream.H
+++ b/src/OpenFOAM/db/IOstreams/StringStreams/StringStream.H
@@ -215,6 +215,9 @@ public:
 
     // Member Functions
 
+        //- The number of bytes outputted
+        std::streamsize count() { return stream_.tellp(); }
+
         //- Get the string.
         //- As Foam::string instead of std::string (may change in future)
         Foam::string str() const { return Foam::string(stream_.str()); }
diff --git a/src/OpenFOAM/db/IOstreams/Tstreams/ITstream.H b/src/OpenFOAM/db/IOstreams/Tstreams/ITstream.H
index 1ec2d0feb8..37e5571e8d 100644
--- a/src/OpenFOAM/db/IOstreams/Tstreams/ITstream.H
+++ b/src/OpenFOAM/db/IOstreams/Tstreams/ITstream.H
@@ -499,16 +499,18 @@ public:
 
     // Stream State Functions
 
-        //- Get stream flags - always 0
-        virtual ios_base::fmtflags flags() const override
+        //- Return current stream flags.
+        //- Dummy for token stream, returns 0.
+        virtual std::ios_base::fmtflags flags() const override
         {
-            return ios_base::fmtflags(0);
+            return std::ios_base::fmtflags(0);
         }
 
-        //- Set flags of stream - ignored
-        ios_base::fmtflags flags(const ios_base::fmtflags) override
+        //- Set stream flags, return old stream flags.
+        //- Dummy for token stream, returns 0.
+        std::ios_base::fmtflags flags(std::ios_base::fmtflags) override
         {
-            return ios_base::fmtflags(0);
+            return std::ios_base::fmtflags(0);
         }
 
 
diff --git a/src/OpenFOAM/db/IOstreams/Tstreams/OTstream.H b/src/OpenFOAM/db/IOstreams/Tstreams/OTstream.H
index b369608326..7af4253e98 100644
--- a/src/OpenFOAM/db/IOstreams/Tstreams/OTstream.H
+++ b/src/OpenFOAM/db/IOstreams/Tstreams/OTstream.H
@@ -181,16 +181,18 @@ public:
 
     // Stream State Functions
 
-        //- Get flags of output stream
-        virtual ios_base::fmtflags flags() const override
+        //- Return current stream flags.
+        //- Dummy for token stream, returns 0.
+        virtual std::ios_base::fmtflags flags() const override
         {
-            return ios_base::fmtflags(0);
+            return std::ios_base::fmtflags(0);
         }
 
-        //- Set flags of stream - ignored
-        std::ios_base::fmtflags flags(const ios_base::fmtflags) override
+        //- Set stream flags, return old stream flags.
+        //- Dummy for token stream, returns 0.
+        std::ios_base::fmtflags flags(std::ios_base::fmtflags) override
         {
-            return ios_base::fmtflags(0);
+            return std::ios_base::fmtflags(0);
         }
 
         //- Flush stream
diff --git a/src/OpenFOAM/db/IOstreams/dummy/dummyISstream.H b/src/OpenFOAM/db/IOstreams/dummy/dummyISstream.H
index 6b50f50c6b..ba9fce3320 100644
--- a/src/OpenFOAM/db/IOstreams/dummy/dummyISstream.H
+++ b/src/OpenFOAM/db/IOstreams/dummy/dummyISstream.H
@@ -73,16 +73,18 @@ public:
 
     // Stream-state
 
-        //- Return flags of stream
-        virtual ios_base::fmtflags flags() const override
+        //- Return current stream flags.
+        //- Dummy for dummy stream, returns 0.
+        virtual std::ios_base::fmtflags flags() const override
         {
-            return ios_base::fmtflags(0);
+            return std::ios_base::fmtflags(0);
         }
 
-        //- Set flags of stream
-        virtual ios_base::fmtflags flags(const ios_base::fmtflags) override
+        //- Set stream flags, return old stream flags.
+        //- Dummy for dummy stream, returns 0.
+        virtual std::ios_base::fmtflags flags(std::ios_base::fmtflags) override
         {
-            return ios_base::fmtflags(0);
+            return std::ios_base::fmtflags(0);
         }
 
 
diff --git a/src/OpenFOAM/db/error/IOerror.C b/src/OpenFOAM/db/error/IOerror.C
index ebde730a09..23029959ff 100644
--- a/src/OpenFOAM/db/error/IOerror.C
+++ b/src/OpenFOAM/db/error/IOerror.C
@@ -30,15 +30,15 @@ Note
 \*---------------------------------------------------------------------------*/
 
 #include "error.H"
-#include "StringStream.H"
 #include "fileName.H"
 #include "dictionary.H"
 #include "JobInfo.H"
 #include "Pstream.H"
+#include "StringStream.H"
 
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
-Foam::IOerror::IOerror(const string& title)
+Foam::IOerror::IOerror(const char* title)
 :
     error(title),
     ioFileName_("unknown"),
@@ -171,7 +171,7 @@ void Foam::IOerror::SafeFatalIOError
     const char* sourceFileName,
     const int sourceFileLineNumber,
     const IOstream& ioStream,
-    const string& msg
+    const std::string& msg
 )
 {
     if (JobInfo::constructed)
@@ -182,10 +182,11 @@ void Foam::IOerror::SafeFatalIOError
             sourceFileName,
             sourceFileLineNumber,
             ioStream
-        )   << msg << Foam::exit(FatalIOError);
+        )   << msg.c_str() << Foam::exit(FatalIOError);
     }
     else
     {
+        // Without (openfoam=API patch=NN) since it is rarely used
         std::cerr
             << nl
             << "--> FOAM FATAL IO ERROR:" << nl
@@ -225,7 +226,7 @@ void Foam::IOerror::exiting(const int errNo, const bool isAbort)
             IOerror errorException(*this);
 
             // Reset the message buffer for the next error message
-            messageStreamPtr_->reset();
+            error::clear();
 
             throw errorException;
             return;
@@ -297,7 +298,7 @@ void Foam::IOerror::write(Ostream& os, const bool withTitle) const
 
     const label lineNo = sourceFileLineNumber();
 
-    if (IOerror::level >= 2 && lineNo && !functionName().empty())
+    if (messageStream::level >= 2 && lineNo && !functionName().empty())
     {
         os  << nl << nl
             << "    From " << functionName().c_str() << nl;
diff --git a/src/OpenFOAM/db/error/error.C b/src/OpenFOAM/db/error/error.C
index 120ac2427a..c4f327c95d 100644
--- a/src/OpenFOAM/db/error/error.C
+++ b/src/OpenFOAM/db/error/error.C
@@ -123,7 +123,7 @@ bool Foam::error::useAbort()
 
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
-Foam::error::error(const string& title)
+Foam::error::error(const char* title)
 :
     std::exception(),
     messageStream(title, messageStream::FATAL),
@@ -131,7 +131,7 @@ Foam::error::error(const string& title)
     sourceFileName_("unknown"),
     sourceFileLineNumber_(0),
     throwing_(false),
-    messageStreamPtr_(new OStringStream())
+    messageStreamPtr_(nullptr)
 {}
 
 
@@ -143,7 +143,7 @@ Foam::error::error(const dictionary& errDict)
     sourceFileName_(errDict.get<string>("sourceFileName")),
     sourceFileLineNumber_(errDict.get<label>("sourceFileLineNumber")),
     throwing_(false),
-    messageStreamPtr_(new OStringStream())
+    messageStreamPtr_(nullptr)
 {}
 
 
@@ -155,8 +155,13 @@ Foam::error::error(const error& err)
     sourceFileName_(err.sourceFileName_),
     sourceFileLineNumber_(err.sourceFileLineNumber_),
     throwing_(err.throwing_),
-    messageStreamPtr_(new OStringStream(*err.messageStreamPtr_))
-{}
+    messageStreamPtr_(nullptr)
+{
+    if (err.messageStreamPtr_ && (err.messageStreamPtr_->count() > 0))
+    {
+        messageStreamPtr_.reset(new OStringStream(*err.messageStreamPtr_));
+    }
+}
 
 
 // * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
@@ -176,7 +181,7 @@ Foam::OSstream& Foam::error::operator()
     sourceFileName_.clear();
     sourceFileLineNumber_ = -1;
 
-    return operator OSstream&();
+    return this->stream();
 }
 
 
@@ -251,7 +256,7 @@ void Foam::error::exiting(const int errNo, const bool isAbort)
             error errorException(*this);
 
             // Reset the message buffer for the next error message
-            messageStreamPtr_->reset();
+            error::clear();
 
             throw errorException;
             return;
@@ -322,8 +327,11 @@ void Foam::error::simpleExit(const int errNo, const bool isAbort)
 
 Foam::OSstream& Foam::error::stream()
 {
-    // Don't need (messageStreamPtr_) check - always allocated
-    if (!messageStreamPtr_->good())
+    if (!messageStreamPtr_)
+    {
+        messageStreamPtr_ = std::make_unique<OStringStream>();
+    }
+    else if (!messageStreamPtr_->good())
     {
         Perr<< nl
             << "error::stream() : error stream has failed"
@@ -337,13 +345,21 @@ Foam::OSstream& Foam::error::stream()
 
 Foam::string Foam::error::message() const
 {
-    return messageStreamPtr_->str();
+    if (messageStreamPtr_)
+    {
+        return messageStreamPtr_->str();
+    }
+
+    return string();
 }
 
 
 void Foam::error::clear() const
 {
-    return messageStreamPtr_->reset();
+    if (messageStreamPtr_)
+    {
+        messageStreamPtr_->reset();
+    }
 }
 
 
@@ -384,7 +400,7 @@ void Foam::error::write(Ostream& os, const bool withTitle) const
 
     const label lineNo = sourceFileLineNumber();
 
-    if (error::level >= 2 && lineNo && !functionName().empty())
+    if (messageStream::level >= 2 && lineNo && !functionName().empty())
     {
         os  << nl << nl
             << "    From " << functionName().c_str() << nl;
diff --git a/src/OpenFOAM/db/error/error.H b/src/OpenFOAM/db/error/error.H
index 21dfea45f1..22832dd8e4 100644
--- a/src/OpenFOAM/db/error/error.H
+++ b/src/OpenFOAM/db/error/error.H
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2015 OpenFOAM Foundation
-    Copyright (C) 2015-2023 OpenCFD Ltd.
+    Copyright (C) 2015-2024 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -120,7 +120,10 @@ public:
     // Constructors
 
         //- Construct from title string
-        explicit error(const string& title);
+        explicit error(const char* title);
+
+        //- Construct from title string
+        explicit error(const std::string& title) : error(title.c_str()) {}
 
         //- Construct from dictionary
         explicit error(const dictionary& errDict);
@@ -161,7 +164,7 @@ public:
         //- The accumulated error message
         string message() const;
 
-        //- Clear any messages
+        //- Clear any accumulated error messages
         void clear() const;
 
         //- The currently defined function name for output messages
@@ -315,7 +318,10 @@ public:
     // Constructors
 
         //- Construct from title string
-        explicit IOerror(const string& title);
+        explicit IOerror(const char* title);
+
+        //- Construct from title string
+        explicit IOerror(const std::string& title) : IOerror(title.c_str()) {}
 
         //- Construct from dictionary
         explicit IOerror(const dictionary& errDict);
@@ -412,7 +418,7 @@ public:
             const char* sourceFileName,
             const int sourceFileLineNumber,
             const IOstream& ioStream,
-            const string& msg
+            const std::string& msg
         );
 
 
diff --git a/src/OpenFOAM/db/error/messageStream.C b/src/OpenFOAM/db/error/messageStream.C
index 2401debdf4..04a3e907bd 100644
--- a/src/OpenFOAM/db/error/messageStream.C
+++ b/src/OpenFOAM/db/error/messageStream.C
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2017-2023 OpenCFD Ltd.
+    Copyright (C) 2017-2024 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -49,22 +49,32 @@ int Foam::infoDetailLevel(1);
 
 Foam::messageStream::messageStream
 (
-    const string& title,
-    const errorSeverity severity,
-    const int maxErrors
+    const char* title,
+    errorSeverity severity,
+    int maxErrors,
+    bool use_stderr
 )
 :
-    title_(title),
+    title_(),
     severity_(severity),
     maxErrors_(maxErrors),
     errorCount_(0)
-{}
+{
+    if (title)
+    {
+        title_ = title;
+    }
+    if (use_stderr)
+    {
+        severity_ |= errorSeverity::USE_STDERR;
+    }
+}
 
 
 Foam::messageStream::messageStream(const dictionary& dict)
 :
     title_(dict.get<string>("title")),
-    severity_(FATAL),
+    severity_(errorSeverity::FATAL),
     maxErrors_(0),
     errorCount_(0)
 {}
@@ -72,54 +82,56 @@ Foam::messageStream::messageStream(const dictionary& dict)
 
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
-Foam::OSstream& Foam::messageStream::stream(OSstream* alternative)
+Foam::OSstream& Foam::messageStream::stream
+(
+    OSstream* alternative
+)
 {
     if (level)
     {
         // Serlal (master only) output?
         const bool serialOnly
         (
-            (
-                severity_ == INFO
-             || severity_ == INFO_STDERR
-             || severity_ == WARNING
-            )
-         || !UPstream::parRun()
+            !UPstream::parRun()
+         || ((severity_ & ~errorSeverity::USE_STDERR) == errorSeverity::INFO)
+         || ((severity_ & ~errorSeverity::USE_STDERR) == errorSeverity::WARNING)
         );
 
         if (serialOnly && (UPstream::parRun() && !UPstream::master()))
         {
-            return Snull; // Non-serial, non-master: exit early
+            return Snull;  // Non-serial, non-master: exit early
         }
 
 
         // Use stderr instead of stdout:
         // - requested via static <redirect> variable
-        // - explicit:  INFO_STDERR
+        // - explicit:  with USE_STDERR mask
         // - inferred:  WARNING -> stderr when infoDetailLevel == 0
-        const bool useStderr =
+        const bool use_stderr =
         (
             (redirect == 2)
-         || (severity_ == INFO_STDERR)
-         || (severity_ == WARNING && Foam::infoDetailLevel == 0)
+         || (severity_ & errorSeverity::USE_STDERR)
+         || (severity_ == errorSeverity::WARNING && Foam::infoDetailLevel == 0)
         );
 
+
         OSstream* osptr;
 
         if (serialOnly)
         {
             // Use supplied alternative? Valid for serial only
-            osptr = alternative;
 
-            if (!osptr)
-            {
-                osptr = (useStderr ? &Serr : &Sout);
-            }
+            osptr =
+            (
+                alternative
+              ? alternative
+              : (use_stderr ? &Serr : &Sout)
+            );
         }
         else
         {
             // Non-serial
-            osptr = (useStderr ? &Perr : &Pout);
+            osptr = (use_stderr ? &Perr : &Pout);
         }
 
         if (!title_.empty())
@@ -220,13 +232,18 @@ Foam::OSstream& Foam::messageStream::deprecated
         }
     }
 
-    os  << nl;
 
+    os  << nl;
     if (functionName)  // nullptr check
     {
-        os  << "    From " << functionName << nl
-            << "    in file " << sourceFileName
-            << " at line " << sourceFileLineNumber << nl;
+        {
+            os  << "    From " << functionName << nl;
+        }
+        if (sourceFileName)
+        {
+            os  << "    in file " << sourceFileName
+                << " at line " << sourceFileLineNumber << nl;
+        }
     }
     os  << "    ";
 
@@ -279,13 +296,14 @@ Foam::OSstream& Foam::messageStream::operator()
     const label ioEndLineNumber
 )
 {
-    OSstream& os = this->stream();
+    OSstream& os = operator()
+    (
+        functionName,
+        sourceFileName,
+        sourceFileLineNumber
+    );
 
-    os  << nl
-        << "    From " << functionName << nl
-        << "    in file " << sourceFileName
-        << " at line " << sourceFileLineNumber << nl
-        << "    Reading \"" << ioFileName.c_str() << '"';
+    os  << "Reading \"" << ioFileName.c_str() << '"';
 
     if (ioStartLineNumber >= 0)
     {
@@ -345,9 +363,19 @@ Foam::OSstream& Foam::messageStream::operator()
 
 // * * * * * * * * * * * * * * * Global Variables  * * * * * * * * * * * * * //
 
-Foam::messageStream Foam::Info("", Foam::messageStream::INFO);
+Foam::messageStream Foam::Info
+(
+    "",  // No title
+    Foam::messageStream::INFO
+);
 
-Foam::messageStream Foam::InfoErr("", Foam::messageStream::INFO_STDERR);
+Foam::messageStream Foam::InfoErr
+(
+    "",  // No title
+    Foam::messageStream::INFO,
+    0,
+    true  // use_stderr = true
+);
 
 Foam::messageStream Foam::Warning
 (
diff --git a/src/OpenFOAM/db/error/messageStream.H b/src/OpenFOAM/db/error/messageStream.H
index be382ec536..9cc61264f0 100644
--- a/src/OpenFOAM/db/error/messageStream.H
+++ b/src/OpenFOAM/db/error/messageStream.H
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2016-2023 OpenCFD Ltd.
+    Copyright (C) 2016-2024 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -77,16 +77,18 @@ class messageStream
 public:
 
     //- Message type, error severity flags
-    enum errorSeverity
+    enum errorSeverity : int
     {
         // Serial-only output:
         INFO = 1,       //!< General information output (stdout)
-        INFO_STDERR,    //!< General information output (stderr)
         WARNING,        //!< Warning of possible problem.
 
         // Parallel-aware output:
         SERIOUS,        //!< A serious problem - eg, data corruption.
-        FATAL           //!< A fatal error.
+        FATAL,          //!< A fatal error.
+
+        //! Bitmask for stderr output (for the above enums)
+        USE_STDERR = 0x80
     };
 
 
@@ -94,9 +96,16 @@ protected:
 
     // Protected Data
 
+        //- The title of this error type
         string title_;
-        errorSeverity severity_;
+
+        //- The message type / error severity, possibly with USE_STDERR mask
+        int severity_;
+
+        //- The maximum number of errors before program termination
         int maxErrors_;
+
+        //- The current number of errors counted
         int errorCount_;
 
 
@@ -124,12 +133,26 @@ public:
         //- Construct from components
         messageStream
         (
-            const string& title,
-            const errorSeverity severity,
-            const int maxErrors = 0
+            const char* title,
+            errorSeverity severity,
+            int maxErrors = 0,
+            bool use_stderr = false
         );
 
-        //- Construct as Fatal from dictionary, extracting the 'title'.
+        //- Construct from components
+        messageStream
+        (
+            const std::string& title,
+            errorSeverity severity,
+            int maxErrors = 0,
+            bool use_stderr = false
+        )
+        :
+            messageStream(title.c_str(), severity, maxErrors, use_stderr)
+        {}
+
+
+        //- Construct from dictionary as Fatal, extracting 'title'.
         explicit messageStream(const dictionary& dict);
 
 
@@ -160,9 +183,11 @@ public:
     // Output
 
         //- Return OSstream for output operations.
-        //- Use the \c alternative stream for serial-only output
-        //- if it is a valid pointer.
-        OSstream& stream(OSstream* alternative = nullptr);
+        OSstream& stream
+        (
+            //! An alternative output stream (serial-only)
+            OSstream* alternative = nullptr
+        );
 
         //- Return OSstream for output operations on the master process only,
         //- Snull on other processes.
@@ -177,11 +202,12 @@ public:
         OSstream& deprecated
         (
             const int afterVersion,
-            const char* functionName,
-            const char* sourceFileName,
+            const char* functionName = nullptr,
+            const char* sourceFileName = nullptr,
             const int sourceFileLineNumber = 0
         );
 
+
         //- Implicit cast to OSstream for << operations
         operator OSstream&()
         {
@@ -261,7 +287,7 @@ public:
 
 //- Global for selective suppression of Info output.
 //  This is normally accessed implicitly via the DetailInfo macro and is often
-//  associated applications with suppressed banners. For example,
+//  associated with applications with suppressed banners. For example,
 //
 //  \code
 //      DetailInfo << "Hello, I'm running from program xyz" << nl;
diff --git a/src/optimisation/adjointOptimisation/adjoint/objectives/objective/objective.C b/src/optimisation/adjointOptimisation/adjoint/objectives/objective/objective.C
index 6045ec353b..fafdf44dcb 100644
--- a/src/optimisation/adjointOptimisation/adjoint/objectives/objective/objective.C
+++ b/src/optimisation/adjointOptimisation/adjoint/objectives/objective/objective.C
@@ -538,9 +538,8 @@ bool objective::write(const bool valid) const
         {
             setObjectiveFilePtr();
             OFstream& file = objFunctionFilePtr_();
-            ios_base::fmtflags flags = file.flags();
-            flags |= std::cout.left;
-            file.flags(flags);
+            file.setf(std::ios_base::left);
+
             if (target_)
             {
                 file<< setw(width_) << "#target" << " "
diff --git a/src/sampling/probes/probes.C b/src/sampling/probes/probes.C
index b4b8e5e95c..01c3ce70d3 100644
--- a/src/sampling/probes/probes.C
+++ b/src/sampling/probes/probes.C
@@ -105,7 +105,7 @@ void Foam::probes::createProbeFiles(const wordList& fieldNames)
             DebugInfo<< "open probe stream: " << os.name() << endl;
 
             const unsigned int width(IOstream::defaultPrecision() + 7);
-            os  << setf(ios_base::left);
+            os.setf(std::ios_base::left);
 
             forAll(*this, probei)
             {