std::basic_spanbuf<CharT,Traits>::basic_spanbuf - cppreference.com (original) (raw)

basic_spanbuf() : basic_spanbuf(std::ios_base::in | std::ios_base::out) {} (1) (since C++23)
explicit basic_spanbuf( std::ios_base::openmode which ) : basic_spanbuf(std::span<CharT>{}, which) {} (2) (since C++23)
explicit basic_spanbuf( std::span<CharT> buf, std::ios_base::openmode which = std::ios_base::in | std::ios_base::out ); (3) (since C++23)
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(affecting pointers to get area) Return value after setting
eback() gptr() egptr()
std::ios_base::in s.data() s.data() s.data() + s.size()
Set bits in open mode(affecting pointers to put area) Return value after setting
pbase() pptr() epptr()
std::ios_base::out && std::ios\_base::ate s.data() s.data() s.data() + s.size()
std::ios_base::out && std::ios_base::ate s.data() s.data() + s.size() s.data() + s.size()

  1. Copy constructor is deleted. basic_spanbuf is not copyable.

  2. 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.

[edit] Parameters

buf - a std::span referencing the underlying buffer
rhs - another basic_spanbuf
which - 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 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

[edit] Notes

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

[edit] Example

[edit] See also

| | constructs the basic_ispanstream (public member function of std::basic_ispanstream<CharT,Traits>) [edit] | | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | | constructs the basic_ospanstream (public member function of std::basic_ospanstream<CharT,Traits>) [edit] | | | constructs the basic_spanstream (public member function of std::basic_spanstream<CharT,Traits>) [edit] |