Similar to OStringStream but using an externally managed buffer for its output. More...

Inheritance diagram for OSpanStream:

Collaboration diagram for OSpanStream:

Public Member Functions
	OSpanStream (IOstreamOption streamOpt=IOstreamOption())
	Default construct (empty output) More...

	OSpanStream (std::string &buffer, IOstreamOption streamOpt=IOstreamOption())
	Use data area from string content. More...

	OSpanStream (char *buffer, size_t nbytes, IOstreamOption streamOpt=IOstreamOption())
	Construct using specified buffer and number of bytes. More...

	OSpanStream (::Foam::UList< char > &buffer, IOstreamOption streamOpt=IOstreamOption())
	Construct using data area from a List and its inherent storage size. More...

template<int SizeMin>
	OSpanStream (::Foam::DynamicList< char, SizeMin > &buffer, IOstreamOption streamOpt=IOstreamOption())
	Construct using full data area from DynamicList. More...

std::streampos	tellp () const
	Position of the put buffer. More...

std::streampos	output_pos () const
	The current output position within the buffer (tellp) More...

label	size () const
	The current output size. Same as tellp(), output_pos() More...

std::streamsize	capacity () const
	The put buffer capacity. More...

UList< char >	list () const
	Span of the current output characters (is modifiable!) More...

auto	view () const -> decltype(stream_.view())
	A string_view (c++17) or span view (older c++) of buffer contents. More...

auto	str () const -> decltype(stream_.str())
	For OStringStream compatibility, return buffer as string copy. More...

void	reset (char *buffer, size_t nbytes)
	Reset the put area. More...

void	reset (std::string &s)
	Reset the put buffer area to use the data area from a string. More...

virtual void	rewind ()
	Rewind the stream, clearing any old errors. More...

virtual void	print (Ostream &os) const override
	Print stream description to Ostream. More...

Public Member Functions inherited from OSstream
	OSstream (const OSstream &)=default
	Copy construct. More...

void	operator= (const OSstream &)=delete
	No copy assignment. More...

	OSstream (std::ostream &os, const string &streamName, IOstreamOption streamOpt=IOstreamOption())
	Construct wrapper around std::ostream, set stream status. More...

	OSstream (std::ostream &os, const string &streamName, IOstreamOption::streamFormat fmt, IOstreamOption::compressionType cmp=IOstreamOption::UNCOMPRESSED)
	Construct wrapper around std::ostream, set stream status. More...

	OSstream (std::ostream &os, const string &streamName, IOstreamOption::streamFormat fmt, IOstreamOption::versionNumber ver, IOstreamOption::compressionType cmp=IOstreamOption::UNCOMPRESSED)
	Construct wrapper around std::ostream, set stream status. More...

virtual const fileName &	name () const override
	Get the name of the output serial stream. (eg, the name of the Fstream file name) More...

virtual const std::ostream &	stdStream () const
	Const access to underlying std::ostream. More...

virtual std::ostream &	stdStream ()
	Access to underlying std::ostream. More...

virtual ios_base::fmtflags	flags () const override
	Get stream flags. More...

virtual ios_base::fmtflags	flags (const ios_base::fmtflags f) override
	Set stream flags. More...

void	syncState ()
	Set stream state to match that of the std::ostream. More...

virtual bool	write (const token &tok) override
	Write token to stream or otherwise handle it. More...

virtual Ostream &	write (const char c) override
	Write character. More...

virtual Ostream &	writeQuoted (const char *str, std::streamsize len, const bool quoted=true) override
	Write character/string content, with/without surrounding quotes. More...

virtual Ostream &	write (const char *str) override
	Write character string. More...

virtual Ostream &	write (const word &str) override
	Write word. More...

virtual Ostream &	write (const std::string &str) override
	Write string (quoted) More...

virtual Ostream &	write (const int32_t val) override
	Write int32_t. More...

virtual Ostream &	write (const int64_t val) override
	Write int64_t. More...

virtual Ostream &	write (const float val) override
	Write float. More...

virtual Ostream &	write (const double val) override
	Write double. More...

virtual Ostream &	write (const char *data, std::streamsize count) override
	Write binary block. More...

virtual Ostream &	writeRaw (const char *data, std::streamsize count) override
	Low-level raw binary output. More...

virtual bool	beginRawWrite (std::streamsize count) override
	Begin marker for low-level raw binary output. More...

virtual bool	endRawWrite () override
	End marker for low-level raw binary output. More...

virtual void	indent () override
	Add indentation characters. More...

virtual void	flush () override
	Flush stream. More...

virtual void	endl () override
	Add newline and flush stream. More...

virtual char	fill () const override
	Get the current padding character. More...

virtual char	fill (const char fillch) override
	Set padding character for formatted field up to field width. More...

virtual int	width () const override
	Get width of output field. More...

virtual int	width (const int w) override
	Set width of output field. More...

virtual int	precision () const override
	Get precision of output field. More...

virtual int	precision (const int p) override
	Set precision of output field. More...

virtual Ostream &	writeQuoted (const char *str, std::streamsize len, const bool quoted=true)=0
	Inherit write methods from Ostream. More...

virtual Ostream &	writeQuoted (const std::string &str, const bool quoted=true)
	Inherit write methods from Ostream. More...

Public Member Functions inherited from Ostream
	Ostream (const Ostream &)=default
	Copy construct. More...

virtual	~Ostream ()=default
	Destructor. More...

	Ostream (IOstreamOption streamOpt=IOstreamOption())
	Default construct (ASCII, uncompressed), construct with specified stream option. More...

	Ostream (IOstreamOption::streamFormat fmt, IOstreamOption::compressionType cmp=IOstreamOption::UNCOMPRESSED)
	Construct with format (uncompressed) More...

virtual Ostream &	writeQuoted (const std::string &str, const bool quoted=true)
	Write string content, with/without surrounding quotes. More...

virtual Ostream &	write (const keyType &kw)
	Write keyType. More...

unsigned short	indentSize () const noexcept
	Return indent size (spaces per level) More...

unsigned short	indentSize (unsigned short val) noexcept
	Change indent size (spaces per level), return old value. More...

unsigned short	indentLevel () const noexcept
	Return the indent level. More...

unsigned short	indentLevel (unsigned short val) noexcept
	Change the indent level, return old value. More...

void	incrIndent () noexcept
	Increment the indent level. More...

void	decrIndent ()
	Decrement the indent level. More...

virtual Ostream &	writeKeyword (const keyType &kw)
	Write the keyword followed by an appropriate indentation. More...

virtual Ostream &	beginBlock (const keyType &kw)
	Write begin block group with the given name. More...

virtual Ostream &	beginBlock ()
	Write begin block group without a name. More...

virtual Ostream &	endBlock ()
	Write end block group. More...

virtual Ostream &	endEntry ()
	Write end entry (';') followed by newline. More...

template<class T >
Ostream &	writeEntry (const keyType &key, const T &value)
	Write a keyword/value entry. More...

template<class T >
Ostream &	writeEntryIfDifferent (const word &key, const T &value1, const T &value2)
	Write a keyword/value entry only when the two values differ. More...

Ostream &	operator() () const
	Return a non-const reference to const Ostream. More...

unsigned short &	indentLevel () noexcept
	Access to indent level. More...

unsigned short &	indentSize () noexcept
	Access to indent size. More...

Public Member Functions inherited from IOstream
	IOstream (const IOstream &)=default
	Copy construct. More...

virtual	~IOstream ()=default
	Destructor. More...

	IOstream (IOstreamOption streamOpt=IOstreamOption())
	Default construct (ASCII, uncompressed), construct with specified stream option. More...

	IOstream (IOstreamOption::streamFormat fmt, IOstreamOption::versionNumber ver, IOstreamOption::compressionType cmp=IOstreamOption::UNCOMPRESSED)
	Construct with format, version (compression) More...

fileName	relativeName () const
	Return the name of the stream relative to the current case. More...

virtual bool	check (const char *operation) const
	Check IOstream status for given operation. More...

bool	fatalCheck (const char *operation) const
	Check IOstream status for given operation. More...

bool	opened () const noexcept
	True if stream has been opened. More...

bool	closed () const noexcept
	True if stream is closed. More...

bool	good () const noexcept
	True if next operation might succeed. More...

bool	eof () const noexcept
	True if end of input seen. More...

bool	fail () const noexcept
	True if next operation will fail. More...

bool	bad () const noexcept
	True if stream is corrupted. More...

	operator bool () const noexcept
	Return true if the stream has not failed. More...

bool	operator! () const noexcept
	Return true if the stream has failed. More...

unsigned	labelByteSize () const noexcept
	The sizeof (label) in bytes associated with the stream. More...

unsigned	scalarByteSize () const noexcept
	The sizeof (scalar) in bytes associated with the stream. More...

void	setLabelByteSize (unsigned nbytes) noexcept
	Set the sizeof (label) in bytes associated with the stream. More...

void	setScalarByteSize (unsigned nbytes) noexcept
	Set the sizeof (scalar) in bytes associated with the stream. More...

template<class T = label>
std::enable_if< std::is_integral< T >::value, bool >::type	checkLabelSize () const noexcept
	Check if the label byte-size associated with the stream is the same as the given type. More...

template<class T = scalar>
std::enable_if< std::is_floating_point< T >::value, bool >::type	checkScalarSize () const noexcept
	Check if the scalar byte-size associated with the stream is the same as the given type. More...

label	lineNumber () const noexcept
	Const access to the current stream line number. More...

label &	lineNumber () noexcept
	Non-const access to the current stream line number. More...

label	lineNumber (const label num) noexcept
	Set the stream line number. More...

void	setEof () noexcept
	Set stream state as reached 'eof'. More...

void	setFail () noexcept
	Set stream state as 'failed'. More...

void	setBad ()
	Set stream state to be 'bad'. More...

ios_base::fmtflags	setf (const ios_base::fmtflags f)
	Set flags of stream. More...

ios_base::fmtflags	setf (const ios_base::fmtflags f, const ios_base::fmtflags mask)
	Set flags of given field of stream. More...

void	unsetf (const ios_base::fmtflags f)
	Unset flags of stream. More...

void	print (Ostream &os, const int streamState) const
	Print information about the stream state bits. More...

InfoProxy< IOstream >	info () const noexcept
	Return info proxy, used to print IOstream information to a stream. More...

Public Member Functions inherited from IOstreamOption
constexpr	IOstreamOption (streamFormat fmt=streamFormat::ASCII, compressionType comp=compressionType::UNCOMPRESSED) noexcept
	Default construct (ASCII, UNCOMPRESSED, currentVersion) or construct with format, compression. More...

constexpr	IOstreamOption (streamFormat fmt, compressionType comp, versionNumber ver) noexcept
	Construct from components (format, compression, version) More...

constexpr	IOstreamOption (streamFormat fmt, versionNumber ver, compressionType comp=compressionType::UNCOMPRESSED) noexcept
	Construct from components (format, version, compression) More...

	IOstreamOption (const IOstreamOption &opt, streamFormat fmt) noexcept
	Copy construct with change of format. More...

streamFormat	format () const noexcept
	Get the current stream format. More...

streamFormat	format (const streamFormat fmt) noexcept
	Set the stream format. More...

streamFormat	format (const word &formatName)
	Set the stream format from string value. More...

compressionType	compression () const noexcept
	Get the stream compression. More...

compressionType	compression (const compressionType comp) noexcept
	Set the stream compression. More...

compressionType	compression (const word &compName)
	Set the stream compression from string value. More...

versionNumber	version () const noexcept
	Get the stream version. More...

versionNumber	version (const versionNumber ver) noexcept
	Set the stream version. More...

versionNumber	version (const token &tok)
	Set the stream version from token. More...

Additional Inherited Members
Public Types inherited from IOstream
enum	streamAccess : char { CLOSED = 0, OPENED }
	Enumeration for stream open/closed state. More...

Public Types inherited from IOstreamOption
enum	streamFormat : char { ASCII = 0, BINARY }
	Data format (ascii \| binary) More...

enum	compressionType : char { UNCOMPRESSED = 0, COMPRESSED }
	Compression treatment (UNCOMPRESSED \| COMPRESSED) More...

enum	appendType : char { NON_APPEND = 0, APPEND }
	File appending (NON_APPEND \| APPEND) More...

enum	atomicType : char { NON_ATOMIC = 0, ATOMIC }
	Atomic operations (output) More...

enum	floatFormat : unsigned { general = unsigned(0), fixed = unsigned(std::ios_base::fixed), scientific = unsigned(std::ios_base::scientific) }
	Float formats (eg, time directory name formats) More...

Static Public Member Functions inherited from IOstream
static unsigned int	defaultPrecision () noexcept
	Return the default precision. More...

static unsigned int	defaultPrecision (unsigned int prec) noexcept
	Reset the default precision. More...

Static Public Member Functions inherited from IOstreamOption
static floatFormat	floatFormatEnum (const word &fmtName, const floatFormat deflt=floatFormat::general)
	Lookup floatFormat enum corresponding to the string (general \| fixed \| scientific). More...

static floatFormat	floatFormatEnum (const word &key, const dictionary &dict, const floatFormat deflt=floatFormat::general)
	getOrDefault floatFormat from dictionary, warn only on bad enumeration. More...

static streamFormat	formatEnum (const word &fmtName, const streamFormat deflt=streamFormat::ASCII)
	Lookup streamFormat enum corresponding to the string (ascii \| binary). More...

static streamFormat	formatEnum (const word &key, const dictionary &dict, const streamFormat deflt=streamFormat::ASCII)
	getOrDefault streamFormat from dictionary, warn only on bad enumeration. More...

static compressionType	compressionEnum (const word &compName, const compressionType deflt=compressionType::UNCOMPRESSED)
	The compression enum corresponding to the string. More...

static compressionType	compressionEnum (const word &key, const dictionary &dict, const compressionType deflt=compressionType::UNCOMPRESSED)
	getOrDefault compressionType from dictionary, warn only on bad enumeration. More...

Static Public Attributes inherited from IOstream
static unsigned int	precision_
	Default precision. More...

Static Public Attributes inherited from IOstreamOption
static const Enum< floatFormat >	floatFormatNames
	Names for float formats (general, fixed, scientific) More...

static const Enum< streamFormat >	formatNames
	Stream format names (ascii, binary) More...

static const versionNumber	currentVersion
	The current version number (2.0) More...

Protected Member Functions inherited from OSpanStreamAllocator
	OSpanStreamAllocator ()=default
	Default construct (empty) More...

Protected Member Functions inherited from IOstream
void	setOpened () noexcept
	Set stream opened. More...

void	setClosed () noexcept
	Set stream closed. More...

void	setState (std::ios_base::iostate state) noexcept
	Set stream state. More...

void	setGood () noexcept
	Set stream state to be good. More...

Protected Attributes inherited from OSpanStreamAllocator
Foam::ospanstream	stream_
	The stream. More...

Protected Attributes inherited from Ostream
unsigned short	indentSize_ = 4
	Number of spaces per indent level. More...

unsigned short	indentLevel_ = 0
	Current indent level. More...

Protected Attributes inherited from IOstream
std::ios_base::iostate	ioState_
	Mirror of internal stream io state. More...

streamAccess	openClosed_
	The stream open/closed state. More...

unsigned char	sizeofLabel_
	The sizeof (label), possibly read from the header. More...

unsigned char	sizeofScalar_
	The sizeof (scalar), possibly read from the header. More...

label	lineNumber_
	The file line. More...

Static Protected Attributes inherited from Ostream
static constexpr const unsigned short	entryIndentation_ = 16
	Indentation of the entry from the start of the keyword. More...

Static Protected Attributes inherited from IOstream
static fileName	staticName_
	Name for any generic stream - normally treat as readonly. More...

Detailed Description

Similar to OStringStream but using an externally managed buffer for its output.

This allows the output buffer to be reused and can make it easier when writing out data. It is the user's responsibility to ensure proper synchronization in the sizes. Provided that the external buffer is large enough that overflow does not occur, the following usage pattern works.

DynamicList<char> buffer(4096);     // allocate some large buffer
{
    OSpanStream os(buffer);
    os << "content1" << " and more content";
    buffer.resize(os.size());       // synchronize sizes
}
something.write(buffer, buffer.size());

Although the OSpanStream is quite lightweight, there may be cases where it is preferable to reuse the stream as well.

DynamicList<char> buffer(4096);     // allocate some large buffer
OSpanStream os(buffer);
os << "content1" << " and more content";
buffer.resize(os.size());           // synchronize sizes
something.write(buffer, buffer.size());
os.rewind();
os << "content2";
buffer.resize(os.size());      // synchronize sizes
something.write(buffer, buffer.size());
// or simply using the output size directly (without sync)
os.rewind();
os << "content3";
something.write(buffer, os.size());