NAME¶

std::basic_spanbuf::basic_spanbuf - std::basic_spanbuf::basic_spanbuf

Synopsis¶

basic_spanbuf() : basic_spanbuf(std::ios_base::in | (1) (since C++23)
std::ios_base::out) {}
explicit basic_spanbuf( std::ios_base::openmode which ) (2) (since C++23)
: basic_spanbuf(std::span<CharT>{}, which) {}
explicit basic_spanbuf( std::span<CharT> buf,
std::ios_base::openmode which = (3) (since C++23)
std::ios_base::in | std::ios_base::out
);
basic_spanbuf( const basic_spanbuf& ) = delete; (4) (since C++23)
basic_spanbuf( basic_spanbuf&& rhs ); (5) (since C++23)

1) Default constructor. Creates a basic_spanbuf that has no underlying buffer and is
opened for both input and output. The pointers to get and put area are set to the
null pointer value.
2) Same as (1), except that the basic_spanbuf is opened in mode specified by which.
3) Creates a basic_spanbuf that manages the underlying buffer referenced by buf (or
has no underlying buffer if buf is empty) and is opened in mode specified by which.
The pointers to get and put area are set as following, or to the null pointer value
if not mentioned in the table:

Set bits in open mode Return value after setting
(affecting pointers to get area) eback() gptr() egptr()
std::ios_base::in s.data() s.data() s.data() +
s.size()
Set bits in open mode Return value after setting
(affecting pointers to put area) pbase() pptr() epptr()
std::ios_base::out && s.data() s.data() s.data() +
!std::ios_base::ate s.size()
std::ios_base::out && s.data() s.data() + s.data() +
std::ios_base::ate s.size() s.size()

4) Copy constructor is deleted. basic_spanbuf is not copyable.
5) Move constructor. Move-constructs the std::basic_streambuf base subobject from
that of rhs. The pointers to get and put area, the open mode, and the underlying
buffer (if any) are identical to those in rhs before construction.
It is implementation-defined whether rhs still holds the underlying buffer after the
move-construction.

Parameters¶

buf - a std::span referencing the underlying buffer
rhs - another basic_spanbuf
specifies stream open mode. It is bitmask type, the following constants are
defined:

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

Notes¶

These constructors are typically called by the constructors of
std::basic_ispanstream, std::basic_ospanstream, and std::basic_spanstream.

Example¶

This section is incomplete
Reason: no example

See also¶

constructor constructs the basic_ispanstream
(C++23) (public member function of std::basic_ispanstream<CharT,Traits>)

constructor constructs the basic_ospanstream
(C++23) (public member function of std::basic_ospanstream<CharT,Traits>)

constructor constructs the basic_spanstream
(C++23) (public member function of std::basic_spanstream<CharT,Traits>)

Category:¶

* Todo no example