Detailed Description

This base class is used to provide a unified interface to files,memory buffers,..Please see the derived classes.

This class is largely inspired by Borland VCL "TStream" class.

Apart of the "VCL like" methods, operators ">>" and "<<" have been defined so that simple types (int,bool,char,float,char *,std::string,...) can be directly written and read to and from any CStream easily. Please, it is recomendable to read CSerializable documentation also.

See also: CFileStream, CMemoryStream,CSerializable

Definition at line 41 of file CStream.h.

#include <mrpt/utils/CStream.h>

Inheritance diagram for mrpt::utils::CStream:

Public Types
enum	TSeekOrigin { sFromBeginning = 0, sFromCurrent = 1, sFromEnd = 2 }
	Used in CStream::Seek. More...

Public Member Functions
	CStream ()

virtual	~CStream ()

size_t	ReadBuffer (void *Buffer, size_t Count)
	Reads a block of bytes from the stream into Buffer. More...

template<typename T >
size_t	ReadBufferFixEndianness (T *ptr, size_t ElementCount)
	Reads a sequence of elemental datatypes, taking care of reordering their bytes from the MRPT stream standard (little endianness) to the format of the running architecture. More...

virtual size_t	ReadBufferImmediate (void *Buffer, size_t Count)
	Reads a block of bytes from the stream into Buffer, and returns the amound of bytes actually read, without waiting for more extra bytes to arrive (just those already enqued in the stream). More...

void	WriteBuffer (const void *Buffer, size_t Count)
	Writes a block of bytes to the stream from Buffer. More...

template<typename T >
void	WriteBufferFixEndianness (const T *ptr, size_t ElementCount)
	Writes a sequence of elemental datatypes, taking care of reordering their bytes from the running architecture to MRPT stream standard (little endianness). More...

virtual uint64_t	Seek (uint64_t Offset, CStream::TSeekOrigin Origin=sFromBeginning)=0
	Introduces a pure virtual method for moving to a specified position in the streamed resource. More...

virtual uint64_t	getTotalBytesCount ()=0
	Returns the total amount of bytes in the stream. More...

virtual uint64_t	getPosition ()=0
	Method for getting the current cursor position, where 0 is the first byte and TotalBytesCount-1 the last one. More...

void	WriteObject (const CSerializable *o)
	Writes an object to the stream. More...

void	WriteObject (const CSerializable &o)

CSerializable::Ptr	ReadObject ()
	Reads an object from stream, its class determined at runtime, and returns a smart pointer to the object. More...

template<typename T >
T::Ptr	ReadObject ()
	Reads an object from stream, its class determined at runtime, and returns a smart pointer to the object. More...

template<typename... T>
mrpt::utils::variant< T... >	ReadVariant ()
	Reads a variant from stream, its class determined at runtime, and returns a variant to the object. More...

template<typename T >
void	WriteVariant (T t)
	Writes a Variant to the stream. More...

template<typename T >
T	ReadPOD ()
	Reads a simple POD type and returns by value. More...

void	ReadObject (CSerializable *existingObj)
	Reads an object from stream, where its class must be the same as the supplied object, where the loaded object will be stored in. More...

CStream &	operator<< (const CSerializable::Ptr &pObj)
	Write an object to a stream in the binary MRPT format. More...

CStream &	operator<< (const CSerializable &obj)
	Write an object to a stream in the binary MRPT format. More...

CStream &	operator>> (CSerializable::Ptr &pObj)

CStream &	operator>> (CSerializable &obj)

template<typename STORED_TYPE , typename CAST_TO_TYPE >
void	ReadAsAndCastTo (CAST_TO_TYPE &read_here)
	Read a value from a stream stored in a type different of the target variable, making the conversion via static_cast. More...

virtual int	printf (const char *fmt,...) MRPT_printf_format_check(2
	Writes a string to the stream in a textual form. More...

template<typename CONTAINER_TYPE >
virtual int void	printf_vector (const char *fmt, const CONTAINER_TYPE &V, char separator=',')
	Prints a vector in the format [A,B,C,...] using CStream::printf, and the fmt string for each vector element `T`. More...

void	sendMessage (const utils::CMessage &msg)
	Send a message to the device. More...

bool	receiveMessage (utils::CMessage &msg)
	Tries to receive a message from the device. More...

bool	getline (std::string &out_str)
	Reads from the stream until a ' ' character is found ('' characters are ignored). More...

Protected Member Functions
virtual size_t	Read (void *Buffer, size_t Count)=0
	Introduces a pure virtual method responsible for reading from the stream. More...

virtual size_t	Write (const void *Buffer, size_t Count)=0
	Introduces a pure virtual method responsible for writing to the stream. More...

void	internal_ReadObject (CSerializable *newObj, const std::string &className, bool isOldFormat, int8_t version)
	Read the object. More...

void	internal_ReadObjectHeader (std::string &className, bool &isOldFormat, int8_t &version)
	Read the object Header. More...

Private Member Functions
template<typename RET >
RET	ReadVariant_helper (CSerializable::Ptr &ptr)

template<typename RET , typename T , typename... R>
RET	ReadVariant_helper (CSerializable::Ptr &ptr, std::enable_if_t< is_shared_ptr< T >::value > *=nullptr)

template<typename RET , typename T , typename... R>
RET	ReadVariant_helper (CSerializable::Ptr &ptr, std::enable_if_t<!is_shared_ptr< T >::value > *=nullptr)

Member Enumeration Documentation

◆ TSeekOrigin

enum mrpt::utils::CStream::TSeekOrigin

Used in CStream::Seek.

Enumerator
sFromBeginning
sFromCurrent
sFromEnd

Definition at line 45 of file CStream.h.

Constructor & Destructor Documentation

◆ CStream()

mrpt::utils::CStream::CStream ( )

inline

Definition at line 74 of file CStream.h.

◆ ~CStream()

CStream::~CStream ( )

virtual

Definition at line 35 of file CStream.cpp.

Member Function Documentation

◆ getline()

bool CStream::getline ( std::string & out_str )

Reads from the stream until a '
' character is found ('' characters are ignored).

Returns: false on EOF or any other read error.

Definition at line 780 of file CStream.cpp.

◆ getPosition()

virtual uint64_t mrpt::utils::CStream::getPosition ( )

pure virtual

Method for getting the current cursor position, where 0 is the first byte and TotalBytesCount-1 the last one.

Implemented in mrpt::comms::CSerialPort, mrpt::comms::CInterfaceFTDI, mrpt::comms::CClientTCPSocket, mrpt::synch::CPipeBaseEndPoint, mrpt::utils::CFileStream, mrpt::utils::CFileOutputStream, mrpt::utils::CMemoryStream, mrpt::utils::CFileGZInputStream, mrpt::utils::CFileInputStream, and mrpt::utils::CStdOutStream.

◆ getTotalBytesCount()

virtual uint64_t mrpt::utils::CStream::getTotalBytesCount ( )

pure virtual

Returns the total amount of bytes in the stream.

Implemented in mrpt::comms::CSerialPort, mrpt::comms::CInterfaceFTDI, mrpt::comms::CClientTCPSocket, mrpt::synch::CPipeBaseEndPoint, mrpt::utils::CFileStream, mrpt::utils::CFileOutputStream, mrpt::utils::CMemoryStream, mrpt::utils::CFileGZInputStream, mrpt::utils::CFileInputStream, and mrpt::utils::CStdOutStream.

◆ internal_ReadObject()

void CStream::internal_ReadObject	(	CSerializable *	newObj,
		const std::string &	className,
		bool	isOldFormat,
		int8_t	version
	)

protected

Read the object.

Definition at line 523 of file CStream.cpp.

References SERIALIZATION_END_FLAG, THROW_EXCEPTION, THROW_EXCEPTION_FMT, and THROW_TYPED_EXCEPTION.

Referenced by ReadObject(), and ReadVariant().

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◆ internal_ReadObjectHeader()

void CStream::internal_ReadObjectHeader	(	std::string &	className,
		bool &	isOldFormat,
		int8_t &	version
	)

protected

Read the object Header.

Definition at line 420 of file CStream.cpp.

References ASSERT_, THROW_EXCEPTION, THROW_STACKED_EXCEPTION_CUSTOM_MSG2, and THROW_TYPED_EXCEPTION.

Referenced by ReadObject(), and ReadVariant().

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◆ operator<<() [1/2]

CStream & CStream::operator<< ( const CSerializable::Ptr & pObj )

Write an object to a stream in the binary MRPT format.

Definition at line 201 of file CStream.cpp.

◆ operator<<() [2/2]

CStream & CStream::operator<< ( const CSerializable & obj )

Write an object to a stream in the binary MRPT format.

Definition at line 208 of file CStream.cpp.

◆ operator>>() [1/2]

CStream & CStream::operator>> ( CSerializable::Ptr & pObj )

Definition at line 214 of file CStream.cpp.

◆ operator>>() [2/2]

CStream & CStream::operator>> ( CSerializable & obj )

Definition at line 220 of file CStream.cpp.

◆ printf()

int CStream::printf	(	const char *	fmt,
			...
	)

virtual

Writes a string to the stream in a textual form.

See also: CStdOutStream

Definition at line 597 of file CStream.cpp.

References MRPT_END, MRPT_START, and vsnprintf.

◆ printf_vector()

template<typename CONTAINER_TYPE >

virtual int void mrpt::utils::CStream::printf_vector	(	const char *	fmt,
		const CONTAINER_TYPE &	V,
		char	separator = `','`
	)

inline

Prints a vector in the format [A,B,C,...] using CStream::printf, and the fmt string for each vector element T.

Template Parameters

CONTAINER_TYPE can be any vector<T>, deque<T> or alike.

Definition at line 370 of file CStream.h.

References printf().

Referenced by mrpt::hmtslam::CTopLCDetector_GridMatching::computeTopologicalObservationModel().

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◆ Read()

virtual size_t mrpt::utils::CStream::Read	(	void *	Buffer,
		size_t	Count
	)

protectedpure virtual

Introduces a pure virtual method responsible for reading from the stream.

Implemented in mrpt::comms::CInterfaceFTDI, mrpt::comms::CSerialPort, mrpt::synch::CPipeBaseEndPoint, mrpt::comms::CClientTCPSocket, mrpt::utils::CFileStream, mrpt::utils::CStdOutStream, mrpt::utils::CFileGZInputStream, mrpt::utils::CMemoryStream, mrpt::utils::CFileOutputStream, and mrpt::utils::CFileInputStream.

◆ ReadAsAndCastTo()

template<typename STORED_TYPE , typename CAST_TO_TYPE >

void mrpt::utils::CStream::ReadAsAndCastTo ( CAST_TO_TYPE & read_here )

inline

Read a value from a stream stored in a type different of the target variable, making the conversion via static_cast.

Useful for coding backwards compatible de-serialization blocks

Definition at line 353 of file CStream.h.

◆ ReadBuffer()

size_t CStream::ReadBuffer	(	void *	Buffer,
		size_t	Count
	)

Reads a block of bytes from the stream into Buffer.

Exceptions

std::exception On any error, or if ZERO bytes are read.

Returns: The amound of bytes actually read.

Note: This method is endianness-dependent.

See also: ReadBufferImmediate ; Important, see: ReadBufferFixEndianness,

Definition at line 40 of file CStream.cpp.

References ASSERT_, and THROW_EXCEPTION.

Referenced by mrpt::hwdrivers::CHokuyoURG::assureBufferHasBytes(), mrpt::compress::zip::compress_gz_data_block(), mrpt::compress::zip::decompress(), mrpt::compress::zip::decompress_gz_file(), mrpt::hwdrivers::CGPSInterface::doProcess(), fill_input_buffer(), mrpt::system::loadBinaryFile(), mrpt::utils::CMemoryStream::loadBufferFromFile(), mrpt::hwdrivers::CHokuyoURG::purgeBuffers(), ReadBufferFixEndianness(), and ReadBufferImmediate().

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◆ ReadBufferFixEndianness()

template<typename T >

size_t mrpt::utils::CStream::ReadBufferFixEndianness	(	T *	ptr,
		size_t	ElementCount
	)

inline

Reads a sequence of elemental datatypes, taking care of reordering their bytes from the MRPT stream standard (little endianness) to the format of the running architecture.

Parameters

ElementCount	The number of elements (not bytes) to read.
ptr	A pointer to the first output element in an array (or std::vector<>, etc...).

Returns: The amound of bytes (not elements) actually read (under error situations, the last element may be invalid if the data stream abruptly ends). Example of usage:
uint32_t N;
s >> N;
vector<float> vec(N);
if (N)
s.ReadBufferFixEndianness<float>(&vec[0],N);

Exceptions

std::exception On any error, or if ZERO bytes are read.

See also: ReadBufferFixEndianness, ReadBuffer

Definition at line 108 of file CStream.h.

References ReadBuffer(), and mrpt::mrpt::utils::reverseBytesInPlace().

Referenced by mrpt::math::operator>>(), ReadPOD(), and triangle_readFromStream().

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◆ ReadBufferImmediate()

virtual size_t mrpt::utils::CStream::ReadBufferImmediate	(	void *	Buffer,
		size_t	Count
	)

inlinevirtual

Reads a block of bytes from the stream into Buffer, and returns the amound of bytes actually read, without waiting for more extra bytes to arrive (just those already enqued in the stream).

Note that this method will fallback to ReadBuffer() in most CStream classes but in some hardware-related classes.

Exceptions

std::exception On any error, or if ZERO bytes are read.

Reimplemented in mrpt::comms::CInterfaceFTDI.

Definition at line 129 of file CStream.h.

References ReadBuffer().

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◆ ReadObject() [1/3]

CSerializable::Ptr mrpt::utils::CStream::ReadObject ( )

inline

Reads an object from stream, its class determined at runtime, and returns a smart pointer to the object.

Exceptions

std::exception	On I/O error or undefined class.
mrpt::utils::CExceptionEOF	On an End-Of-File condition found at a correct place: an EOF that abruptly finishes in the middle of one object raises a plain std::exception instead.

Definition at line 207 of file CStream.h.

Referenced by mrpt::utils::mrpt_recv_from_zmq(), mrpt::utils::mrpt_recv_from_zmq_into(), mrpt::utils::OctetVectorToObject(), mrpt::utils::operator>>(), mrpt::nav::CAbstractPTGBasedReactive::performNavigationStep(), mrpt::utils::RawStringToObject(), mrpt::utils::StringToObject(), and TEST().

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◆ ReadObject() [2/3]

template<typename T >

T::Ptr mrpt::utils::CStream::ReadObject ( )

inline

Reads an object from stream, its class determined at runtime, and returns a smart pointer to the object.

This version is similar to mrpt::make_aligned_shared<T>.

Exceptions

std::exception	On I/O error or undefined class.
mrpt::utils::CExceptionEOF	On an End-Of-File condition found at a correct place: an EOF that abruptly finishes in the middle of one object raises a plain std::exception instead.

Definition at line 217 of file CStream.h.

References mrpt::utils::TRuntimeClassId::createObject(), mrpt::utils::findRegisteredClass(), internal_ReadObject(), and internal_ReadObjectHeader().

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◆ ReadObject() [3/3]

void CStream::ReadObject ( CSerializable * existingObj )

Reads an object from stream, where its class must be the same as the supplied object, where the loaded object will be stored in.

Exceptions

std::exception	On I/O error or different class found.
mrpt::utils::CExceptionEOF	On an End-Of-File condition found at a correct place: an EOF that abruptly finishes in the middle of one object raises a plain std::exception instead.

Definition at line 566 of file CStream.cpp.

References ASSERT_, mrpt::utils::TRuntimeClassId::className, mrpt::utils::findRegisteredClass(), mrpt::format(), mrpt::utils::CSerializable::GetRuntimeClass(), THROW_EXCEPTION, and THROW_EXCEPTION_FMT.

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◆ ReadPOD()

template<typename T >

T mrpt::utils::CStream::ReadPOD ( )

inline

Reads a simple POD type and returns by value.

Useful when stream >> var; cannot be used becuase of errors of misaligned reference binding. Use with macro MRPT_READ_POD to avoid typing the type T yourself.

Note: [New in MRPT 2.0.0]; Write operator s << var; is safe for misaligned variables.

Definition at line 325 of file CStream.h.

References ReadBufferFixEndianness().

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◆ ReadVariant()

template<typename... T>

mrpt::utils::variant<T...> mrpt::utils::CStream::ReadVariant ( )

inline

Reads a variant from stream, its class determined at runtime, and returns a variant to the object.

To be compatible with the current polymorphic system this support smart pointer types. For pointer types, This will bind to the first possible pointer type. variant<CSerializable::Ptr, CRenderizable::Ptr>

Exceptions

std::exception	On I/O error or undefined class.
mrpt::utils::CExceptionEOF	On an End-Of-File condition found at a correct place: an EOF that abruptly finishes in the middle of one object raises a plain std::exception instead.

Definition at line 282 of file CStream.h.

References mrpt::utils::TRuntimeClassId::createObject(), mrpt::utils::findRegisteredClass(), internal_ReadObject(), internal_ReadObjectHeader(), ReadVariant_helper(), and THROW_EXCEPTION_FMT.

Referenced by mrpt::utils::operator>>().

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◆ ReadVariant_helper() [1/3]

template<typename RET >

RET mrpt::utils::CStream::ReadVariant_helper ( CSerializable::Ptr & ptr )

inlineprivate

Definition at line 244 of file CStream.h.

References THROW_EXCEPTION.

Referenced by ReadVariant(), and ReadVariant_helper().

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◆ ReadVariant_helper() [2/3]

template<typename RET , typename T , typename... R>

RET mrpt::utils::CStream::ReadVariant_helper	(	CSerializable::Ptr &	ptr,
		std::enable_if_t< is_shared_ptr< T >::value > *	= `nullptr`
	)

inlineprivate

Definition at line 251 of file CStream.h.

References IS_CLASS, R, and ReadVariant_helper().

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◆ ReadVariant_helper() [3/3]

template<typename RET , typename T , typename... R>

RET mrpt::utils::CStream::ReadVariant_helper	(	CSerializable::Ptr &	ptr,
		std::enable_if_t<!is_shared_ptr< T >::value > *	= `nullptr`
	)

inlineprivate

Definition at line 261 of file CStream.h.

References IS_CLASS, R, and ReadVariant_helper().

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◆ receiveMessage()

bool CStream::receiveMessage ( utils::CMessage & msg )

Tries to receive a message from the device.

Exceptions

std::exception On communication errors

Returns: True if successful, false if there is no new data from the device (but communications seem to work fine)

See also: The frame format is described in sendMessage()

Definition at line 686 of file CStream.cpp.

References mrpt::utils::CMessage::content, MAKEWORD16B, mrpt::system::os::memcpy(), MRPT_END, MRPT_START, and mrpt::utils::CMessage::type.

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◆ Seek()

virtual uint64_t mrpt::utils::CStream::Seek	(	uint64_t	Offset,
		CStream::TSeekOrigin	Origin = `sFromBeginning`
	)

pure virtual

Introduces a pure virtual method for moving to a specified position in the streamed resource.

he Origin parameter indicates how to interpret the Offset parameter. Origin should be one of the following values:

sFromBeginning (Default) Offset is from the beginning of the resource. Seek moves to the position Offset. Offset must be >= 0.
sFromCurrent Offset is from the current position in the resource. Seek moves to Position + Offset.
sFromEnd Offset is from the end of the resource. Offset must be <= 0 to indicate a number of bytes before the end of the file.
Returns
Seek returns the new value of the Position property.

Implemented in mrpt::utils::CFileStream, mrpt::utils::CFileGZInputStream, mrpt::utils::CFileOutputStream, mrpt::utils::CMemoryStream, mrpt::utils::CFileInputStream, and mrpt::utils::CStdOutStream.

◆ sendMessage()

void CStream::sendMessage ( const utils::CMessage & msg )

Send a message to the device.

Note that only the low byte from the "type" field will be used.

For frames of size < 255 the frame format is an array of bytes in this order:

<START_FLAG> <HEADER> <LENGTH> <BODY> <END_FLAG>
       <START_FLAG>    = 0x69
       <HEADER>                = A header byte
       <LENGHT>                = Number of bytes of BODY
       <BODY>                  = N x bytes
       <END_FLAG>              = 0X96
Total length   =       <LENGTH> + 4

For frames of size > 255 the frame format is an array of bytes in this order:

 <START_FLAG> <HEADER> <HIBYTE(LENGTH)> <LOBYTE(LENGTH)> <BODY>
<END_FLAG>
        <START_FLAG>    = 0x79
        <HEADER>                = A header byte
        <LENGHT>                = Number of bytes of BODY
        <BODY>                  = N x bytes
        <END_FLAG>              = 0X96
 Total length   =       <LENGTH> + 5

Exceptions

std::exception On communication errors

Definition at line 649 of file CStream.cpp.

References mrpt::utils::CMessage::content, mrpt::system::os::memcpy(), MRPT_END, MRPT_START, and mrpt::utils::CMessage::type.

Referenced by mrpt::hwdrivers::CServoeNeck::disableServo(), mrpt::hwdrivers::CServoeNeck::enableServo(), mrpt::hwdrivers::CRoboticHeadInterface::Get3SoundBuffer(), mrpt::hwdrivers::CRoboticHeadInterface::GetGain(), mrpt::hwdrivers::CServoeNeck::getRegisterValue(), mrpt::hwdrivers::CRoboticHeadInterface::GetSoundLocation(), mrpt::hwdrivers::CServoeNeck::queryFirmwareVersion(), mrpt::hwdrivers::CBoardENoses::queryFirmwareVersion(), mrpt::hwdrivers::CRoboticHeadInterface::SetGain(), mrpt::hwdrivers::CServoeNeck::setRegisterValue(), and mrpt::hwdrivers::CServoeNeck::setRegisterValueAndSpeed().

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◆ Write()

virtual size_t mrpt::utils::CStream::Write	(	const void *	Buffer,
		size_t	Count
	)

protectedpure virtual

Introduces a pure virtual method responsible for writing to the stream.

Write attempts to write up to Count bytes to Buffer, and returns the number of bytes actually written.

Implemented in mrpt::comms::CInterfaceFTDI, mrpt::comms::CSerialPort, mrpt::synch::CPipeBaseEndPoint, mrpt::comms::CClientTCPSocket, mrpt::utils::CFileStream, mrpt::utils::CStdOutStream, mrpt::utils::CFileGZInputStream, mrpt::utils::CMemoryStream, mrpt::utils::CFileOutputStream, and mrpt::utils::CFileInputStream.

◆ WriteBuffer()

void CStream::WriteBuffer	(	const void *	Buffer,
		size_t	Count
	)

Writes a block of bytes to the stream from Buffer.

Exceptions

std::exception On any error

See also: Important, see: WriteBufferFixEndianness

Note: This method is endianness-dependent.

Definition at line 64 of file CStream.cpp.

References ASSERT_, and THROW_EXCEPTION.

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◆ WriteBufferFixEndianness()

template<typename T >

void mrpt::utils::CStream::WriteBufferFixEndianness	(	const T *	ptr,
		size_t	ElementCount
	)

inline

Writes a sequence of elemental datatypes, taking care of reordering their bytes from the running architecture to MRPT stream standard (little endianness).

Parameters

ElementCount	The number of elements (not bytes) to write.
ptr	A pointer to the first input element in an array (or std::vector<>, etc...). Example of usage: vector<float> vec = ... uint32_t N = vec.size(); s << N if (N) s.WriteBufferFixEndianness<float>(&vec[0],N);