ENH: consolidate stream allocators

- add count() member for output span streams (consistency)

- ITstream construct/parse from span/view

COMP: remove old/unused first()/last() methods from SubStrings

src/OpenFOAM/db/IOstreams/Fstreams/fstreamPointer.H

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2020-2023 OpenCFD Ltd.
+    Copyright (C) 2020-2024 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -132,7 +132,7 @@ public:
     // Member Functions
 
         //- True if compiled with libz support
-        static bool supports_gz();
+        static bool supports_gz() noexcept;
 
 
     // Access
@@ -276,7 +276,7 @@ public:
     // Member Functions
 
         //- True if compiled with libz support
-        static bool supports_gz();
+        static bool supports_gz() noexcept;
 
 
     // Access

src/OpenFOAM/db/IOstreams/Fstreams/fstreamPointers.C

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011 OpenFOAM Foundation
-    Copyright (C) 2018-2023 OpenCFD Ltd.
+    Copyright (C) 2018-2024 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -40,7 +40,7 @@ License
 
 // * * * * * * * * * * * * * Static Member Functions * * * * * * * * * * * * //
 
-bool Foam::ifstreamPointer::supports_gz()
+bool Foam::ifstreamPointer::supports_gz() noexcept
 {
     #ifdef HAVE_LIBZ
     return true;
@@ -50,7 +50,7 @@ bool Foam::ifstreamPointer::supports_gz()
 }
 
 
-bool Foam::ofstreamPointer::supports_gz()
+bool Foam::ofstreamPointer::supports_gz() noexcept
 {
     #ifdef HAVE_LIBZ
     return true;
@@ -71,7 +71,7 @@ Foam::ifstreamPointer::ifstreamPointer
     IOstreamOption streamOpt  // Currently unused
 )
 :
-    ptr_(nullptr)
+    ptr_()
 {
     open(pathname, streamOpt);
 }
@@ -82,7 +82,7 @@ Foam::ifstreamPointer::ifstreamPointer
     const fileName& pathname
 )
 :
-    ptr_(nullptr)
+    ptr_()
 {
     open(pathname);
 }
@@ -110,7 +110,7 @@ Foam::ofstreamPointer::ofstreamPointer
     const bool atomic
 )
 :
-    ptr_(nullptr),
+    ptr_(),
     atomic_(atomic)
 {
     std::ios_base::openmode mode

src/OpenFOAM/db/IOstreams/IOstreams/IOstream.H

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2015 OpenFOAM Foundation
-    Copyright (C) 2018-2022 OpenCFD Ltd.
+    Copyright (C) 2018-2024 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -468,6 +468,41 @@ inline IOstream& scientific(IOstream& io)
 namespace Detail
 {
 
+/*---------------------------------------------------------------------------*\
+                   Class Detail::StreamAllocator Declaration
+\*---------------------------------------------------------------------------*/
+
+//- A wrapper to hold a std::stream type for OpenFOAM wrapped streams.
+//- This is necessary since the OpenFOAM streams hold a reference to
+//- the normal std::stream
+template<class StreamType>
+class StreamAllocator
+{
+protected:
+
+    // Protected Data
+
+        //- The std::stream
+        StreamType stream_;
+
+
+    // Constructors
+
+        //- Default construct (empty)
+        StreamAllocator() = default;
+};
+
+
+} // End namespace Detail
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+// Functions/Algorithms
+
+namespace Detail
+{
+
 //- Termination for input looping (no-op)
 template<class IS> inline void inputLoop(IS&) {}
 

src/OpenFOAM/db/IOstreams/StringStreams/StringStream.H

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2017-2022 OpenCFD Ltd.
+    Copyright (C) 2017-2024 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -46,60 +46,6 @@ SourceFiles
 namespace Foam
 {
 
-namespace Detail
-{
-
-/*---------------------------------------------------------------------------*\
-                Class Detail::StringStreamAllocator Declaration
-\*---------------------------------------------------------------------------*/
-
-//- Allocator for variants of a std stringstream
-template<class StreamType>
-class StringStreamAllocator
-{
-protected:
-
-    // Protected Member Data
-
-        //- The stream type
-        typedef StreamType stream_type;
-
-        //- The input/output stream.
-        stream_type stream_;
-
-
-    // Constructors
-
-        //- Default construct
-        StringStreamAllocator() = default;
-
-        //- Copy construct from string
-        StringStreamAllocator(const std::string& s)
-        :
-            stream_(s)
-        {}
-
-
-public:
-
-    // Member Functions
-
-        //- Get the string - as Foam::string rather than std::string
-        Foam::string str() const
-        {
-            return Foam::string(stream_.str());
-        }
-
-        //- Set the string
-        void str(const std::string& s)
-        {
-            stream_.str(s);
-        }
-};
-
-} // End namespace Detail
-
-
 /*---------------------------------------------------------------------------*\
                         Class IStringStream Declaration
 \*---------------------------------------------------------------------------*/
@@ -107,10 +53,12 @@ public:
 //- Input from string buffer, using a ISstream. Always UNCOMPRESSED.
 class IStringStream
 :
-    public Detail::StringStreamAllocator<std::istringstream>,
+    public Foam::Detail::StreamAllocator<std::istringstream>,
-    public ISstream
+    public Foam::ISstream
 {
-    typedef Detail::StringStreamAllocator<std::istringstream> allocator_type;
+    typedef
+        Foam::Detail::StreamAllocator<std::istringstream>
+        allocator_type;
 
 public:
 
@@ -133,9 +81,11 @@ public:
             IOstreamOption streamOpt = IOstreamOption()
         )
         :
-            allocator_type(s),
+            allocator_type(),
             ISstream(stream_, "input", streamOpt.format(), streamOpt.version())
-        {}
+        {
+            stream_.str(s);
+        }
 
         //- Construct from char*
         explicit IStringStream
@@ -144,20 +94,32 @@ public:
             IOstreamOption streamOpt = IOstreamOption()
         )
         :
-            allocator_type(s),
+            allocator_type(),
             ISstream(stream_, "input", streamOpt.format(), streamOpt.version())
-        {}
+        {
+            stream_.str(s);
+        }
 
         //- Copy construct, copies content and format
         IStringStream(const IStringStream& str)
         :
-            allocator_type(str.str()),
+            allocator_type(),
             ISstream(stream_, str.name(), static_cast<IOstreamOption>(str))
-        {}
+        {
+            stream_.str(str.str());
+        }
 
 
     // Member Functions
 
+        //- Get the string.
+        //- As Foam::string instead of std::string (may change in future)
+        Foam::string str() const { return Foam::string(stream_.str()); }
+
+        //- Set the string
+        void str(const std::string& s) { stream_.str(s); }
+
+
         //- Reset the input buffer and rewind the stream
         virtual void reset(const std::string& s)
         {
@@ -220,10 +182,12 @@ public:
 //- Output to string buffer, using a OSstream. Always UNCOMPRESSED.
 class OStringStream
 :
-    public Detail::StringStreamAllocator<std::ostringstream>,
+    public Foam::Detail::StreamAllocator<std::ostringstream>,
-    public OSstream
+    public Foam::OSstream
 {
-    typedef Detail::StringStreamAllocator<std::ostringstream> allocator_type;
+    typedef
+        Foam::Detail::StreamAllocator<std::ostringstream>
+        allocator_type;
 
 public:
 
@@ -242,13 +206,23 @@ public:
         //- Copy construct, copies content and format
         OStringStream(const OStringStream& str)
         :
-            allocator_type(str.str()),
+            allocator_type(),
             OSstream(stream_, str.name(), static_cast<IOstreamOption>(str))
-        {}
+        {
+            stream_.str(str.str());
+        }
 
 
     // Member Functions
 
+        //- Get the string.
+        //- As Foam::string instead of std::string (may change in future)
+        Foam::string str() const { return Foam::string(stream_.str()); }
+
+        //- Set the string
+        void str(const std::string& s) { stream_.str(s); }
+
+
         //- Reset the output buffer and rewind the stream
         void reset()
         {

src/OpenFOAM/db/IOstreams/Tstreams/ITstream.C

@@ -91,13 +91,14 @@ Foam::ITstream& Foam::ITstream::empty_stream()
 }
 
 
-Foam::tokenList Foam::ITstream::parse
+Foam::tokenList Foam::ITstream::parse_chars
 (
-    const UList<char>& input,
+    const char* s,
+    size_t nbytes,
     IOstreamOption streamOpt
 )
 {
-    ISpanStream is(input, streamOpt);
+    ISpanStream is(s, nbytes, streamOpt);
 
     tokenList tokens;
     parseStream(is, tokens);
@@ -105,31 +106,14 @@ Foam::tokenList Foam::ITstream::parse
 }
 
 
-Foam::tokenList Foam::ITstream::parse
+// * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
-(
+
-    const std::string& input,
+void Foam::ITstream::reset(const char* input, size_t nbytes)
-    IOstreamOption streamOpt
-)
 {
-    ISpanStream is(input, streamOpt);
+    ISpanStream is(input, nbytes, static_cast<IOstreamOption>(*this));
 
-    tokenList tokens;
+    parseStream(is, static_cast<tokenList&>(*this));
-    parseStream(is, tokens);
+    ITstream::seek(0);  // rewind(), but bypasss virtual
-    return tokens;
-}
-
-
-Foam::tokenList Foam::ITstream::parse
-(
-    const char* input,
-    IOstreamOption streamOpt
-)
-{
-    ISpanStream is(input, strlen(input), streamOpt);
-
-    tokenList tokens;
-    parseStream(is, tokens);
-    return tokens;
 }
 
 
@@ -254,10 +238,7 @@ Foam::ITstream::ITstream
 :
     ITstream(streamOpt, name)
 {
-    ISpanStream is(input, streamOpt);
+    reset(input.cdata(), input.size_bytes());
-
-    parseStream(is, static_cast<tokenList&>(*this));
-    ITstream::seek(0);  // rewind(), but bypasss virtual
 }
 
 
@@ -270,10 +251,7 @@ Foam::ITstream::ITstream
 :
     ITstream(streamOpt, name)
 {
-    ISpanStream is(input, streamOpt);
+    reset(input.data(), input.size());
-
-    parseStream(is, static_cast<tokenList&>(*this));
-    ITstream::seek(0);  // rewind(), but bypasss virtual
 }
 
 
@@ -286,10 +264,7 @@ Foam::ITstream::ITstream
 :
     ITstream(streamOpt, name)
 {
-    ISpanStream is(input, strlen(input), streamOpt);
+    reset(input, strlen(input));
-
-    parseStream(is, static_cast<tokenList&>(*this));
-    ITstream::seek(0);  // rewind(), but bypasss virtual
 }
 
 

src/OpenFOAM/db/IOstreams/Tstreams/ITstream.H

@@ -77,6 +77,18 @@ class ITstream
         //  but leave any excess capacity (ie, like reserve).
         void reserveCapacity(const label newCapacity);
 
+        //- Convert input sequence into a list of tokens,
+        static tokenList parse_chars
+        (
+            const char* s,
+            size_t nbytes,
+            IOstreamOption streamOpt
+        );
+
+        //- Convert input sequence into a list of tokens,
+        //- using the existing stream format. Rewinds the stream
+        void reset(const char* input, size_t nbytes);
+
         //- Failsafe read-access to token at specified location
         //- or undefinedToken
         inline const token& peekNoFail(const label i) const
@@ -158,6 +170,47 @@ public:
             const string& name = "input"
         );
 
+        #if __cplusplus >= 201703L
+        //- Construct token list by parsing the input character sequence
+        //  Uses static parse function internally.
+        explicit ITstream
+        (
+            std::string_view s,
+            IOstreamOption streamOpt = IOstreamOption()
+        )
+        :
+            ITstream(streamOpt)
+        {
+            reset(s.data(), s.size());
+        }
+        #endif
+
+        //- Construct token list by parsing the input character sequence
+        //  Uses static parse function internally.
+        explicit ITstream
+        (
+            stdFoam::span<char> s,
+            IOstreamOption streamOpt = IOstreamOption()
+        )
+        :
+            ITstream(streamOpt)
+        {
+            reset(s.data(), s.size());
+        }
+
+        //- Construct token list by parsing the input character sequence
+        //  Uses static parse function internally.
+        explicit ITstream
+        (
+            stdFoam::span<const char> s,
+            IOstreamOption streamOpt = IOstreamOption()
+        )
+        :
+            ITstream(streamOpt)
+        {
+            reset(s.data(), s.size());
+        }
+
 
     // Additional constructors
 
@@ -207,7 +260,10 @@ public:
         (
             const UList<char>& input,
             IOstreamOption streamOpt = IOstreamOption()
-        );
+        )
+        {
+            return parse_chars(input.cdata(), input.size(), streamOpt);
+        }
 
         //- Create token list by parsing the input string
         //- until no good tokens remain.
@@ -215,7 +271,10 @@ public:
         (
             const std::string& input,
             IOstreamOption streamOpt = IOstreamOption()
-        );
+        )
+        {
+            return parse_chars(input.data(), input.size(), streamOpt);
+        }
 
         //- Create token list by parsing the input character sequence
         //- until no good tokens remain.
@@ -223,7 +282,45 @@ public:
         (
             const char* input,
             IOstreamOption streamOpt = IOstreamOption()
-        );
+        )
+        {
+            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
+        (
+            std::string_view s,
+            IOstreamOption streamOpt = IOstreamOption()
+        )
+        {
+            return parse_chars(s.data(), s.size(), streamOpt);
+        }
+        #endif
+
+        //- Create token list by parsing the input character sequence
+        //- until no good tokens remain.
+        static tokenList parse
+        (
+            stdFoam::span<char> s,
+            IOstreamOption streamOpt = IOstreamOption()
+        )
+        {
+            return parse_chars(s.data(), s.size(), streamOpt);
+        }
+
+        //- Create token list by parsing the input character sequence
+        //- until no good tokens remain.
+        static tokenList parse
+        (
+            stdFoam::span<const char> s,
+            IOstreamOption streamOpt = IOstreamOption()
+        )
+        {
+            return parse_chars(s.data(), s.size(), streamOpt);
+        }
 
 
     // Member Functions

src/OpenFOAM/db/IOstreams/hashes/OSHA1stream.H

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011 OpenFOAM Foundation
-    Copyright (C) 2019-2023 OpenCFD Ltd.
+    Copyright (C) 2019-2024 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -35,8 +35,8 @@ Description
 #ifndef Foam_OSHA1stream_H
 #define Foam_OSHA1stream_H
 
-#include "OSstream.H"
 #include "SHA1.H"
+#include "OSstream.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -114,33 +114,6 @@ public:
 };
 
 
-namespace Detail
-{
-
-/*---------------------------------------------------------------------------*\
-                Class Detail::OSHA1streamAllocator Declaration
-\*---------------------------------------------------------------------------*/
-
-//- An allocator for holding Foam::osha1stream
-class OSHA1streamAllocator
-{
-protected:
-
-    // Protected Data
-
-        //- The output stream
-        Foam::osha1stream stream_;
-
-
-    // Constructors
-
-        //- Default construct
-        OSHA1streamAllocator() = default;
-};
-
-} // End namespace Detail
-
-
 /*---------------------------------------------------------------------------*\
                          Class OSHA1stream Declaration
 \*---------------------------------------------------------------------------*/
@@ -148,10 +121,12 @@ protected:
 //- The output stream for calculating SHA1 digests
 class OSHA1stream
 :
-    public Detail::OSHA1streamAllocator,
+    public Foam::Detail::StreamAllocator<Foam::osha1stream>,
-    public OSstream
+    public Foam::OSstream
 {
-    typedef Detail::OSHA1streamAllocator allocator_type;
+    typedef
+        Foam::Detail::StreamAllocator<Foam::osha1stream>
+        allocator_type;
 
 public:
 

src/OpenFOAM/db/IOstreams/memory/ICharStream.H

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2017-2023 OpenCFD Ltd.
+    Copyright (C) 2017-2024 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -42,8 +42,6 @@ See Also
 #define Foam_ICharStream_H
 
 #include "ISpanStream.H"
-#include "List.H"
-#include "DynamicList.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -205,33 +203,6 @@ public:
 };
 
 
-namespace Detail
-{
-
-/*---------------------------------------------------------------------------*\
-                Class Detail::ICharStreamAllocator Declaration
-\*---------------------------------------------------------------------------*/
-
-//- An allocator for holding Foam::icharstream
-class ICharStreamAllocator
-{
-protected:
-
-    // Protected Data
-
-        //- The stream
-        Foam::icharstream stream_;
-
-
-    // Constructors
-
-        //- Default construct
-        ICharStreamAllocator() = default;
-};
-
-} // End namespace Detail
-
-
 /*---------------------------------------------------------------------------*\
                          Class ICharStream Declaration
 \*---------------------------------------------------------------------------*/
@@ -239,10 +210,12 @@ protected:
 //- An ISstream with internal List storage. Always UNCOMPRESSED.
 class ICharStream
 :
-    public Detail::ICharStreamAllocator,
+    public Foam::Detail::StreamAllocator<Foam::icharstream>,
     public Foam::ISstream
 {
-    typedef Detail::ICharStreamAllocator allocator_type;
+    typedef
+        Foam::Detail::StreamAllocator<Foam::icharstream>
+        allocator_type;
 
 public:
 

src/OpenFOAM/db/IOstreams/memory/ISpanStream.H

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2016-2023 OpenCFD Ltd.
+    Copyright (C) 2016-2024 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -65,7 +65,6 @@ See Also
 #define Foam_ISpanStream_H
 
 #include "memoryStreamBuffer.H"
-#include "UList.H"
 #include "ISstream.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
@@ -213,49 +212,23 @@ public:
         //- Some information about the input buffer position/capacity
         void debug_info(Ostream& os) const
         {
-            os  << "get="
+            os  << "get=" << input_pos() << '/' << capacity();
-                << input_pos() << '/' << capacity();
         }
 };
 
 
-namespace Detail
-{
-
-/*---------------------------------------------------------------------------*\
-                Class Detail::ISpanStreamAllocator Declaration
-\*---------------------------------------------------------------------------*/
-
-//- An allocator for holding Foam::ispanstream
-class ISpanStreamAllocator
-{
-protected:
-
-    // Protected Data
-
-        //- The stream
-        Foam::ispanstream stream_;
-
-
-    // Constructors
-
-        //- Default construct (empty)
-        ISpanStreamAllocator() = default;
-};
-
-} // End namespace Detail
-
-
 /*---------------------------------------------------------------------------*\
                          Class ISpanStream Declaration
 \*---------------------------------------------------------------------------*/
 
 class ISpanStream
 :
-    public Detail::ISpanStreamAllocator,
+    public Foam::Detail::StreamAllocator<Foam::ispanstream>,
     public Foam::ISstream
 {
-    typedef Detail::ISpanStreamAllocator allocator_type;
+    typedef
+        Foam::Detail::StreamAllocator<Foam::ispanstream>
+        allocator_type;
 
 public:
 

src/OpenFOAM/db/IOstreams/memory/OCharStream.H

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2017-2023 OpenCFD Ltd.
+    Copyright (C) 2017-2024 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -109,7 +109,13 @@ public:
         //- The current output position within the buffer (tellp)
         std::streampos output_pos() const
         {
-            return (buffer_type::span_tellp());
+            return buffer_type::span_tellp();
+        }
+
+        //- The number of bytes outputted
+        std::streamsize count() const
+        {
+            return buffer_type::size_bytes();
         }
 
         //- The put buffer capacity
@@ -189,33 +195,6 @@ public:
 };
 
 
-namespace Detail
-{
-
-/*---------------------------------------------------------------------------*\
-                Class Detail::OCharStreamAllocator Declaration
-\*---------------------------------------------------------------------------*/
-
-//- An allocator for holding Foam::ocharstream
-class OCharStreamAllocator
-{
-protected:
-
-    // Protected Data
-
-        //- The stream
-        Foam::ocharstream stream_;
-
-
-    // Constructors
-
-        //- Default construct - empty
-        OCharStreamAllocator() = default;
-};
-
-} // End namespace Detail
-
-
 /*---------------------------------------------------------------------------*\
                          Class OCharStream Declaration
 \*---------------------------------------------------------------------------*/
@@ -223,10 +202,12 @@ protected:
 //- An OSstream with internal List storage
 class OCharStream
 :
-    public Detail::OCharStreamAllocator,
+    public Foam::Detail::StreamAllocator<Foam::ocharstream>,
     public Foam::OSstream
 {
-    typedef Detail::OCharStreamAllocator allocator_type;
+    typedef
+        Foam::Detail::StreamAllocator<Foam::ocharstream>
+        allocator_type;
 
 public:
 
@@ -277,8 +258,11 @@ public:
         //- The current output position within the buffer (tellp)
         std::streampos output_pos() const { return stream_.output_pos(); }
 
-        //- The current output size. Same as tellp(), output_pos()
+        //- The number of bytes outputted
-        label size() const { return label(stream_.output_pos()); }
+        std::streamsize count() const { return stream_.count(); }
+
+        //- The current output size. Same as count(), output_pos(), tellp().
+        label size() const { return label(stream_.count()); }
 
         //- The put buffer capacity
         std::streamsize capacity() const { return stream_.capacity(); }

src/OpenFOAM/db/IOstreams/memory/OCountStream.H

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2016-2023 OpenCFD Ltd.
+    Copyright (C) 2016-2024 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -35,7 +35,6 @@ Description
 #define Foam_OScountStream_H
 
 #include "OSstream.H"
-#include <iostream>
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -126,7 +125,7 @@ class ocountstream
 
         // Member Functions
 
-            //- The number of bytes counted.
+            //- The number of bytes counted
             std::streamsize count() const noexcept { return size_; }
 
             //- Reset the count
@@ -155,7 +154,7 @@ public:
         //- This hides both signatures of std::basic_ios::rdbuf()
         countbuf* rdbuf() { return &buf_; }
 
-        //- \return The number of bytes counted
+        //- The number of bytes counted
         std::streamsize count() const noexcept { return buf_.count(); }
 
         //- Reset the count
@@ -173,33 +172,6 @@ public:
 };
 
 
-namespace Detail
-{
-
-/*---------------------------------------------------------------------------*\
-                Class Detail::OCountStreamAllocator Declaration
-\*---------------------------------------------------------------------------*/
-
-//- An allocator for holding Foam::ocountstream
-class OCountStreamAllocator
-{
-protected:
-
-    // Protected Data
-
-        //- The output stream
-        Foam::ocountstream stream_;
-
-
-    // Constructors
-
-        //- Default construct
-        OCountStreamAllocator() = default;
-};
-
-} // End namespace Detail
-
-
 /*---------------------------------------------------------------------------*\
                         Class OCountStream Declaration
 \*---------------------------------------------------------------------------*/
@@ -207,10 +179,12 @@ protected:
 //- An output stream for calculating byte counts
 class OCountStream
 :
-    public Detail::OCountStreamAllocator,
+    public Foam::Detail::StreamAllocator<Foam::ocountstream>,
-    public OSstream
+    public Foam::OSstream
 {
-    typedef Detail::OCountStreamAllocator allocator_type;
+    typedef
+        Foam::Detail::StreamAllocator<Foam::ocountstream>
+        allocator_type;
 
 public:
 
@@ -238,10 +212,10 @@ public:
 
     // Member Functions
 
-        //- \return The number of bytes counted
+        //- The number of bytes counted
         std::streamsize count() const noexcept { return stream_.count(); }
 
-        //- \return The number of bytes counted
+        //- The number of bytes counted
         std::streamsize size() const noexcept { return stream_.count(); }
 
         //- Reset the count

src/OpenFOAM/db/IOstreams/memory/OSpanStream.H

@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2016-2023 OpenCFD Ltd.
+    Copyright (C) 2016-2024 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -83,7 +83,6 @@ See Also
 #define Foam_OSpanStream_H
 
 #include "memoryStreamBuffer.H"
-#include "DynamicList.H"
 #include "OSstream.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
@@ -141,6 +140,12 @@ public:
             return buffer_type::span_tellp();
         }
 
+        //- The number of bytes outputted
+        std::streamsize count() const
+        {
+            return buffer_type::size_bytes();
+        }
+
         //- The put buffer capacity
         std::streamsize capacity() const
         {
@@ -199,49 +204,23 @@ public:
         //- Some information about the output buffer position/capacity
         void debug_info(Ostream& os) const
         {
-            os  << "put="
+            os  << "put=" << output_pos() << '/' << capacity();
-                << output_pos() << '/' << capacity();
         }
 };
 
 
-namespace Detail
-{
-
-/*---------------------------------------------------------------------------*\
-                Class Detail::OSpanStreamAllocator Declaration
-\*---------------------------------------------------------------------------*/
-
-//- An allocator for holding Foam::ospanstream
-class OSpanStreamAllocator
-{
-protected:
-
-    // Protected Data
-
-        //- The stream
-        Foam::ospanstream stream_;
-
-
-    // Constructors
-
-        //- Default construct (empty)
-        OSpanStreamAllocator() = default;
-};
-
-} // End namespace Detail
-
-
 /*---------------------------------------------------------------------------*\
                          Class OSpanStream Declaration
 \*---------------------------------------------------------------------------*/
 
 class OSpanStream
 :
-    public Detail::OSpanStreamAllocator,
+    public Foam::Detail::StreamAllocator<Foam::ospanstream>,
     public Foam::OSstream
 {
-    typedef Detail::OSpanStreamAllocator allocator_type;
+    typedef
+        Foam::Detail::StreamAllocator<Foam::ospanstream>
+        allocator_type;
 
 public:
 
@@ -314,8 +293,11 @@ public:
         //- The current output position within the buffer (tellp)
         std::streampos output_pos() const { return stream_.output_pos(); }
 
-        //- The current output size. Same as tellp(), output_pos()
+        //- The number of bytes outputted
-        label size() const { return label(stream_.output_pos()); }
+        std::streamsize count() const { return stream_.count(); }
+
+        //- The current output size. Same as count(), output_pos(), tellp().
+        label size() const { return label(stream_.count()); }
 
         //- The put buffer capacity
         std::streamsize capacity() const { return stream_.capacity(); }

src/OpenFOAM/primitives/strings/lists/SubStrings.H

@@ -109,19 +109,14 @@ public:
             this->push_back(range);
         }
 
-        //- Const reference to the first element,
+    // FUTURE?
-        //- for consistency with other OpenFOAM containers
+    //  #if __cplusplus >= 201703L
-        auto first() const -> decltype(this->front())
+    //  std::string_view view(size_t pos) const
-        {
+    //  {}
-            return this->front();
+    //  #else
-        }
+    //  stdFoam::span<const char> view(size_t pos) const
-
+    //  {}
-        //- Const reference to the last element,
+    //  #endif
-        //- for consistency with other OpenFOAM containers
-        auto last() const -> decltype(this->back())
-        {
-            return this->back();
-        }
 };
 
 

src/surfMesh/MeshedSurfaceAllocator/MeshedSurfaceIOAllocator.C

@@ -63,14 +63,6 @@ Foam::Detail::MeshedSurfaceIOAllocator::MeshedSurfaceIOAllocator
 {}
 
 
-// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
-
-Foam::Detail::MeshedSurfaceIOAllocator::~MeshedSurfaceIOAllocator()
-{
-    clear();
-}
-
-
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
 void Foam::Detail::MeshedSurfaceIOAllocator::setInstance

src/surfMesh/MeshedSurfaceAllocator/MeshedSurfaceIOAllocator.H

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2016-2022 OpenCFD Ltd.
+    Copyright (C) 2016-2024 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -39,7 +39,7 @@ SourceFiles
 #define Foam_MeshedSurfaceIOAllocator_H
 
 #include "pointIOField.H"
-#include "faceIOList.H"
+#include "faceIOList.H"  // faceIOList and faceCompactIOList
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -62,8 +62,9 @@ class MeshedSurfaceIOAllocator
         //- Faces
         faceCompactIOList faces_;
 
+public:
 
-    // Private Member Functions
+    // Generated Methods
 
         //- No copy construct
         MeshedSurfaceIOAllocator(const MeshedSurfaceIOAllocator&) = delete;
@@ -72,8 +73,6 @@ class MeshedSurfaceIOAllocator
         void operator=(const MeshedSurfaceIOAllocator&) = delete;
 
 
-public:
-
     // Constructors
 
         //- Read construct from IOobjects
@@ -99,7 +98,7 @@ public:
 
 
     //- Destructor
-    virtual ~MeshedSurfaceIOAllocator();
+    virtual ~MeshedSurfaceIOAllocator() = default;
 
 
     // Member Functions
@@ -116,25 +115,25 @@ public:
     // Access
 
         //- Non-const access to the points
-        pointIOField& storedIOPoints()
+        pointIOField& storedIOPoints() noexcept
         {
             return points_;
         }
 
         //- Non-const access to the faces
-        faceCompactIOList& storedIOFaces()
+        faceCompactIOList& storedIOFaces() noexcept
         {
             return faces_;
         }
 
         //- Const access to the points
-        const pointIOField& storedIOPoints() const
+        const pointIOField& storedIOPoints() const noexcept
         {
             return points_;
         }
 
         //- Const access to the faces
-        const faceCompactIOList& storedIOFaces() const
+        const faceCompactIOList& storedIOFaces() const noexcept
         {
             return faces_;
         }