161 lines
6.6 KiB
Markdown
161 lines
6.6 KiB
Markdown
[ispanstream]
|
||
|
||
# 31 Input/output library [[input.output]](./#input.output)
|
||
|
||
## 31.9 Span-based streams [[span.streams]](span.streams#ispanstream)
|
||
|
||
### 31.9.4 Class template basic_ispanstream [ispanstream]
|
||
|
||
#### [31.9.4.1](#general) General [[ispanstream.general]](ispanstream.general)
|
||
|
||
[ð](#lib:basic_ispanstream)
|
||
|
||
namespace std {template<class charT, class traits = char_traits<charT>>class basic_ispanstream : public basic_istream<charT, traits> {public:using char_type = charT; using int_type = typename traits::int_type; using pos_type = typename traits::pos_type; using off_type = typename traits::off_type; using traits_type = traits; // [[ispanstream.cons]](#cons "31.9.4.2 Constructors"), constructorsexplicit basic_ispanstream(std::span<charT> s,
|
||
ios_base::openmode which = ios_base::in);
|
||
basic_ispanstream(const basic_ispanstream&) = delete;
|
||
basic_ispanstream(basic_ispanstream&& rhs); template<class ROS> explicit basic_ispanstream(ROS&& s);
|
||
|
||
basic_ispanstream& operator=(const basic_ispanstream&) = delete;
|
||
basic_ispanstream& operator=(basic_ispanstream&& rhs); // [[ispanstream.swap]](#swap "31.9.4.3 Swap"), swapvoid swap(basic_ispanstream& rhs); // [[ispanstream.members]](#members "31.9.4.4 Member functions"), member functions basic_spanbuf<charT, traits>* rdbuf() const noexcept;
|
||
|
||
std::span<const charT> span() const noexcept; void span(std::span<charT> s) noexcept; template<class ROS> void span(ROS&& s) noexcept; private: basic_spanbuf<charT, traits> *sb*; // *exposition only*};}
|
||
|
||
[1](#general-1)
|
||
|
||
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L10440)
|
||
|
||
[*Note [1](#general-note-1)*:
|
||
|
||
Constructing an ispanstream from a [*string-literal*](lex.string#nt:string-literal "5.13.5 String literals [lex.string]") includes the termination character '\0' in the underlying spanbuf[.](#general-1.sentence-1)
|
||
|
||
â *end note*]
|
||
|
||
#### [31.9.4.2](#cons) Constructors [[ispanstream.cons]](ispanstream.cons)
|
||
|
||
[ð](#lib:basic_ispanstream,constructor)
|
||
|
||
`explicit basic_ispanstream(std::span<charT> s, ios_base::openmode which = ios_base::in);
|
||
`
|
||
|
||
[1](#cons-1)
|
||
|
||
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L10455)
|
||
|
||
*Effects*: Initializes the base class withbasic_istream<charT, traits>(addressof(*sb*)) and *sb* withbasic_spanbuf<charT, traits>(s, which | ios_base::in) ([[spanbuf.cons]](spanbuf.cons "31.9.3.2 Constructors"))[.](#cons-1.sentence-1)
|
||
|
||
[ð](#lib:basic_ispanstream,constructor_)
|
||
|
||
`basic_ispanstream(basic_ispanstream&& rhs);
|
||
`
|
||
|
||
[2](#cons-2)
|
||
|
||
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L10469)
|
||
|
||
*Effects*: Initializes the base class with std::move(rhs) and *sb* with std::move(rhs.*sb*)[.](#cons-2.sentence-1)
|
||
|
||
Next, basic_istream<charT, traits>::set_rdbuf(addressof(*sb*)) is called
|
||
to install the contained basic_spanbuf[.](#cons-2.sentence-2)
|
||
|
||
[ð](#lib:basic_ispanstream,constructor__)
|
||
|
||
`template<class ROS> explicit basic_ispanstream(ROS&& s)
|
||
`
|
||
|
||
[3](#cons-3)
|
||
|
||
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L10483)
|
||
|
||
*Constraints*: ROS models ranges::[borrowed_range](range.range#concept:borrowed_range "25.4.2 Ranges [range.range]")[.](#cons-3.sentence-1)
|
||
|
||
<ROS, std::span<charT>> && [convertible_to](concept.convertible#concept:convertible_to "18.4.4 Concept convertible_to [concept.convertible]")<ROS, std::span<charT const>> is true[.](#cons-3.sentence-2)
|
||
|
||
[4](#cons-4)
|
||
|
||
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L10489)
|
||
|
||
*Effects*: Let sp be std::span<const charT>(std::forward<ROS>(s))[.](#cons-4.sentence-1)
|
||
|
||
Equivalent to:basic_ispanstream(std::span<charT>(const_cast<charT*>(sp.data()), sp.size()))
|
||
|
||
#### [31.9.4.3](#swap) Swap [[ispanstream.swap]](ispanstream.swap)
|
||
|
||
[ð](#lib:swap,basic_ispanstream)
|
||
|
||
`void swap(basic_ispanstream& rhs);
|
||
`
|
||
|
||
[1](#swap-1)
|
||
|
||
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L10506)
|
||
|
||
*Effects*: Equivalent to:basic_istream<charT, traits>::swap(rhs);*sb*.swap(rhs.*sb*);
|
||
|
||
[ð](#lib:swap,basic_ispanstream_)
|
||
|
||
`template<class charT, class traits>
|
||
void swap(basic_ispanstream<charT, traits>& x, basic_ispanstream<charT, traits>& y);
|
||
`
|
||
|
||
[2](#swap-2)
|
||
|
||
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L10522)
|
||
|
||
*Effects*: Equivalent to x.swap(y)[.](#swap-2.sentence-1)
|
||
|
||
#### [31.9.4.4](#members) Member functions [[ispanstream.members]](ispanstream.members)
|
||
|
||
[ð](#lib:rdbuf,basic_ispanstream)
|
||
|
||
`basic_spanbuf<charT, traits>* rdbuf() const noexcept;
|
||
`
|
||
|
||
[1](#members-1)
|
||
|
||
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L10535)
|
||
|
||
*Effects*: Equivalent to:return const_cast<basic_spanbuf<charT, traits>*>(addressof(*sb*));
|
||
|
||
[ð](#lib:span,basic_ispanstream)
|
||
|
||
`std::span<const charT> span() const noexcept;
|
||
`
|
||
|
||
[2](#members-2)
|
||
|
||
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L10549)
|
||
|
||
*Effects*: Equivalent to: return rdbuf()->span();
|
||
|
||
[ð](#lib:span,basic_ispanstream_)
|
||
|
||
`void span(std::span<charT> s) noexcept;
|
||
`
|
||
|
||
[3](#members-3)
|
||
|
||
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L10560)
|
||
|
||
*Effects*: Equivalent to rdbuf()->span(s)[.](#members-3.sentence-1)
|
||
|
||
[ð](#members-itemdecl:4)
|
||
|
||
`template<class ROS> void span(ROS&& s) noexcept;
|
||
`
|
||
|
||
[4](#members-4)
|
||
|
||
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L10570)
|
||
|
||
*Constraints*: ROS models ranges::[borrowed_range](range.range#concept:borrowed_range "25.4.2 Ranges [range.range]")[.](#members-4.sentence-1)
|
||
|
||
(<ROS, std::span<charT>>) && [convertible_to](concept.convertible#concept:convertible_to "18.4.4 Concept convertible_to [concept.convertible]")<ROS, std::span<const charT>> is true[.](#members-4.sentence-2)
|
||
|
||
[5](#members-5)
|
||
|
||
[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L10576)
|
||
|
||
*Effects*: Let sp be std::span<const charT>(std::forward<ROS>(s))[.](#members-5.sentence-1)
|
||
|
||
Equivalent to:this->span(std::span<charT>(const_cast<charT*>(sp.data()), sp.size()));
|