Difference between revisions of "cpp/io/basic ispanstream"

Latest revision as of 14:16, 30 October 2024

Defined in header `<spanstream>`
template< class CharT, class Traits = std::char_traits<CharT> > class basic_ispanstream : public basic_istream<CharT, Traits>		(since C++23)

The class template std::basic_ispanstream implements input operations on streams based on fixed buffers.

At the low level, the class essentially wraps a raw device implementation of std::basic_spanbuf into a higher-level interface of std::basic_istream. The complete interface to unique std::basic_spanbuf members is provided.

Inheritance diagram

Several typedefs for common character types are provided:

Defined in header `<spanstream>`
Type	Definition
`std::ispanstream`	std::basic_ispanstream<char>
`std::wispanstream`	std::basic_ispanstream<wchar_t>

[edit] Member types

Member type	Definition
`char_type`	`CharT`[edit]
`traits_type`	`Traits`; the program is ill-formed if `Traits::char_type` is not `CharT`.[edit]
`int_type`	`Traits::int_type`[edit]
`pos_type`	`Traits::pos_type`[edit]
`off_type`	`Traits::off_type`[edit]

[edit] Data members

Member object	Definition
`sb` (private)	The wrapped std::basic_spanbuf. (exposition-only member object*)

[edit] Member functions

(constructor)	constructs the `basic_ispanstream` (public member function) [edit]
(destructor) [virtual]	destroys the `basic_ispanstream` (virtual public member function)
operator=	move-assignments the `basic_ispanstream` (public member function) [edit]
swap	swaps two `basic_ispanstream` objects (public member function) [edit]
rdbuf	obtains the address of the wrapped raw `span` device object (public member function) [edit]
Underlying buffer operations
span	gets or sets the underlying buffer of the wrapped `span` device object (public member function) [edit]

[edit] Non-member functions

std::swap(std::basic_ispanstream)

(C++23)

specializes the std::swap algorithm
(function template) [edit]

Inherited from std::basic_istream

Member functions

Formatted input
operator>>	extracts formatted data (public member function of `std::basic_istream<CharT,Traits>`) [edit]
Unformatted input
get	extracts characters (public member function of `std::basic_istream<CharT,Traits>`) [edit]
peek	reads the next character without extracting it (public member function of `std::basic_istream<CharT,Traits>`) [edit]
unget	unextracts a character (public member function of `std::basic_istream<CharT,Traits>`) [edit]
putback	puts a character into input stream (public member function of `std::basic_istream<CharT,Traits>`) [edit]
getline	extracts characters until the given character is found (public member function of `std::basic_istream<CharT,Traits>`) [edit]
ignore	extracts and discards characters until the given character is found (public member function of `std::basic_istream<CharT,Traits>`) [edit]
read	extracts blocks of characters (public member function of `std::basic_istream<CharT,Traits>`) [edit]
readsome	extracts already available blocks of characters (public member function of `std::basic_istream<CharT,Traits>`) [edit]
gcount	returns number of characters extracted by last unformatted input operation (public member function of `std::basic_istream<CharT,Traits>`) [edit]
Positioning
tellg	returns the input position indicator (public member function of `std::basic_istream<CharT,Traits>`) [edit]
seekg	sets the input position indicator (public member function of `std::basic_istream<CharT,Traits>`) [edit]
Miscellaneous
sync	synchronizes with the underlying storage device (public member function of `std::basic_istream<CharT,Traits>`) [edit]

Member classes

sentry

implements basic logic for preparation of the stream for input operations
(public member class of std::basic_istream<CharT,Traits>) [edit]

Inherited from std::basic_ios

Member types

Member type	Definition
`char_type`	`CharT`
`traits_type`	`Traits`
`int_type`	`Traits::int_type`
`pos_type`	`Traits::pos_type`
`off_type`	`Traits::off_type`

Member functions

State functions
good	checks if no error has occurred i.e. I/O operations are available (public member function of `std::basic_ios<CharT,Traits>`) [edit]
eof	checks if end-of-file has been reached (public member function of `std::basic_ios<CharT,Traits>`) [edit]
fail	checks if an error has occurred (public member function of `std::basic_ios<CharT,Traits>`) [edit]
bad	checks if a non-recoverable error has occurred (public member function of `std::basic_ios<CharT,Traits>`) [edit]
operator!	checks if an error has occurred (synonym of fail()) (public member function of `std::basic_ios<CharT,Traits>`) [edit]
operator bool	checks if no error has occurred (synonym of `!`fail()) (public member function of `std::basic_ios<CharT,Traits>`) [edit]
rdstate	returns state flags (public member function of `std::basic_ios<CharT,Traits>`) [edit]
setstate	sets state flags (public member function of `std::basic_ios<CharT,Traits>`) [edit]
clear	modifies state flags (public member function of `std::basic_ios<CharT,Traits>`) [edit]
Formatting
copyfmt	copies formatting information (public member function of `std::basic_ios<CharT,Traits>`) [edit]
fill	manages the fill character (public member function of `std::basic_ios<CharT,Traits>`) [edit]
Miscellaneous
exceptions	manages exception mask (public member function of `std::basic_ios<CharT,Traits>`) [edit]
imbue	sets the locale (public member function of `std::basic_ios<CharT,Traits>`) [edit]
rdbuf	manages associated stream buffer (public member function of `std::basic_ios<CharT,Traits>`) [edit]
tie	manages tied stream (public member function of `std::basic_ios<CharT,Traits>`) [edit]
narrow	narrows characters (public member function of `std::basic_ios<CharT,Traits>`) [edit]
widen	widens characters (public member function of `std::basic_ios<CharT,Traits>`) [edit]

Inherited from std::ios_base

Member functions

Formatting
flags	manages format flags (public member function of `std::ios_base`) [edit]
setf	sets specific format flag (public member function of `std::ios_base`) [edit]
unsetf	clears specific format flag (public member function of `std::ios_base`) [edit]
precision	manages decimal precision of floating point operations (public member function of `std::ios_base`) [edit]
width	manages field width (public member function of `std::ios_base`) [edit]
Locales
imbue	sets locale (public member function of `std::ios_base`) [edit]
getloc	returns current locale (public member function of `std::ios_base`) [edit]
Internal extensible array
xalloc [static]	returns a program-wide unique integer that is safe to use as index to `pword()` and `iword()` (public static member function of `std::ios_base`) [edit]
iword	resizes the private storage if necessary and access to the long element at the given index (public member function of `std::ios_base`) [edit]
pword	resizes the private storage if necessary and access to the void* element at the given index (public member function of `std::ios_base`) [edit]
Miscellaneous
register_callback	registers event callback function (public member function of `std::ios_base`) [edit]
sync_with_stdio [static]	sets whether C++ and C I/O libraries are interoperable (public static member function of `std::ios_base`) [edit]
Member classes
failure	stream exception (public member class of `std::ios_base`) [edit]
Init	initializes standard stream objects (public member class of `std::ios_base`) [edit]

Member types and constants

Type Explanation

openmode

stream open mode type

The following constants are also defined:

Constant	Explanation[edit]
`app`	seek to the end of stream before each write[edit]
`binary`	open in binary mode[edit]
`in`	open for reading[edit]
`out`	open for writing[edit]
`trunc`	discard the contents of the stream when opening[edit]
`ate`	seek to the end of stream immediately after open[edit]
`noreplace` (C++23)	open in exclusive mode[edit]

(typedef) [edit]

fmtflags

formatting flags type

The following constants are also defined:

Constant	Explanation[edit]
`dec`	use decimal base for integer I/O: see std::dec[edit]
`oct`	use octal base for integer I/O: see std::oct[edit]
`hex`	use hexadecimal base for integer I/O: see std::hex[edit]
`basefield`	dec \| oct \| hex. Useful for masking operations[edit]
`left`	left adjustment (adds fill characters to the right): see std::left[edit]
`right`	right adjustment (adds fill characters to the left): see std::right[edit]
`internal`	internal adjustment (adds fill characters to the internal designated point): see std::internal[edit]
`adjustfield`	left \| right \| internal. Useful for masking operations[edit]
`scientific`	generate floating point types using scientific notation, or hex notation if combined with fixed: see std::scientific[edit]
`fixed`	generate floating point types using fixed notation, or hex notation if combined with scientific: see std::fixed[edit]
`floatfield`	scientific \| fixed. Useful for masking operations[edit]
`boolalpha`	insert and extract bool type in alphanumeric format: see std::boolalpha[edit]
`showbase`	generate a prefix indicating the numeric base for integer output, require the currency indicator in monetary I/O: see std::showbase[edit]
`showpoint`	generate a decimal-point character unconditionally for floating-point number output: see std::showpoint[edit]
`showpos`	generate a + character for non-negative numeric output: see std::showpos[edit]
`skipws`	skip leading whitespace before certain input operations: see std::skipws[edit]
`unitbuf`	flush the output after each output operation: see std::unitbuf[edit]
`uppercase`	replace certain lowercase letters with their uppercase equivalents in certain output operations: see std::uppercase[edit]

(typedef) [edit]

iostate

state of the stream type

The following constants are also defined:

Constant	Explanation[edit]
`goodbit`	no error[edit]
`badbit`	irrecoverable stream error[edit]
`failbit`	input/output operation failed (formatting or extraction error)[edit]
`eofbit`	associated input sequence has reached end-of-file[edit]

(typedef) [edit]

seekdir

seeking direction type

The following constants are also defined:

Constant	Explanation[edit]
`beg`	the beginning of a stream[edit]
`end`	the ending of a stream[edit]
`cur`	the current position of stream position indicator[edit]

(typedef) [edit]

event

specifies event type
(enum) [edit]

event_callback

callback function type
(typedef) [edit]

[edit] Notes

Feature-test macro	Value	Std	Feature
`__cpp_lib_spanstream`	202106L	(C++23)	std::spanbuf, std::spanstream

@@ Line 28: / Line 28: @@
 {{dsc begin}}
 {{dsc inc|cpp/io/basic_spanstream/dsc constructor|basic_ispanstream}}
-{{dsc mem vdtor|cpp/io/basic_ispanstream|notes={{mark c++23}}|inlinemem=true|destroys the {{tt|basic_ispanstream}}}}
+{{dsc mem vdtor|cpp/io/basic_ispanstream|inlinemem=true|destroys the {{tt|basic_ispanstream}}}}
 {{dsc inc|cpp/io/basic_spanstream/dsc operator{{=}}|basic_ispanstream}}
 {{dsc inc|cpp/io/basic_spanstream/dsc swap|basic_ispanstream}}

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I/O manipulators
Print functions (C++23)
C-style I/O
Buffers
basic_streambuf
basic_filebuf
basic_stringbuf
basic_spanbuf (C++23)
strstreambuf (C++98/26*)
basic_syncbuf (C++20)
Streams
Abstractions
ios_base
basic_ios
basic_istream
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basic_iostream
File I/O
basic_ifstream
basic_ofstream
basic_fstream
String I/O
basic_istringstream
basic_ostringstream
basic_stringstream
Array I/O
basic_ispanstream (C++23)
basic_ospanstream (C++23)
basic_spanstream (C++23)
istrstream (C++98/26*)
ostrstream (C++98/26*)
strstream (C++98/26*)
Synchronized Output
basic_osyncstream (C++20)
Types
streamoff
streamsize
fpos
Error category interface
iostream_category (C++11)
io_errc (C++11)

Member functions
basic_ispanstream::basic_ispanstream (C++23)
basic_ispanstream::operator= (C++23)
basic_ispanstream::swap (C++23)
basic_ispanstream::rdbuf (C++23)
Underlying buffer operations
basic_ispanstream::span (C++23)
Non-member functions
swap(std::basic_ipanstream) (C++23)

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Difference between revisions of "cpp/io/basic ispanstream"

Latest revision as of 14:16, 30 October 2024

Contents

[edit] Member types

[edit] Data members

[edit] Member functions

Underlying buffer operations

[edit] Non-member functions

Inherited from std::basic_istream

Member functions

Formatted input

Unformatted input

Positioning

Miscellaneous

Member classes

Inherited from std::basic_ios

Member types

Member functions

State functions

Formatting

Miscellaneous

Inherited from std::ios_base

Member functions

Formatting

Locales

Internal extensible array

Miscellaneous

Member classes

Member types and constants

[edit] Notes

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