[spanbuf.cons]

# 31 Input/output library [[input.output]](./#input.output)

## 31.9 Span-based streams [[span.streams]](span.streams#spanbuf.cons)

### 31.9.3 Class template basic_spanbuf [[spanbuf]](spanbuf#cons)

#### 31.9.3.2 Constructors [spanbuf.cons]

[ð](#lib:basic_spanbuf,constructor)

`explicit basic_spanbuf(std::span<charT> s,
                       ios_base::openmode which = ios_base::in | ios_base::out);
`

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L10147)

*Effects*: Initializes the base class with basic_streambuf() ([[streambuf.cons]](streambuf.cons "31.6.3.2 Constructors")),
and *mode* with which[.](#1.sentence-1)

Initializes the internal pointers as if calling span(s)[.](#1.sentence-2)

[ð](#lib:basic_spanbuf,constructor_)

`basic_spanbuf(basic_spanbuf&& rhs);
`

[2](#2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L10160)

*Effects*: Initializes the base class with std​::​move(rhs) and*mode* with std​::​move(rhs.*mode*) and*buf* with std​::​move(rhs.*buf*)[.](#2.sentence-1)

The sequence pointers in *this (eback(), gptr(), egptr(),pbase(), pptr(), epptr())
obtain the values which rhs had[.](#2.sentence-2)

It isimplementation-defined
whether rhs.*buf*.​empty() returns true after the move[.](#2.sentence-3)

[3](#3)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L10173)

*Postconditions*: Let rhs_p refer to the state of rhs just prior to this construction[.](#3.sentence-1)

- [(3.1)](#3.1)

span().data() == rhs_p.span().data()

- [(3.2)](#3.2)

span().size() == rhs_p.span().size()

- [(3.3)](#3.3)

eback() == rhs_p.eback()

- [(3.4)](#3.4)

gptr() == rhs_p.gptr()

- [(3.5)](#3.5)

egptr() == rhs_p.egptr()

- [(3.6)](#3.6)

pbase() == rhs_p.pbase()

- [(3.7)](#3.7)

pptr() == rhs_p.pptr()

- [(3.8)](#3.8)

epptr() == rhs_p.epptr()

- [(3.9)](#3.9)

getloc() == rhs_p.getloc()
