[ispanstream] (original) (raw)

31 Input/output library [input.output]

31.9 Span-based streams [span.streams]

31.9.4 Class template basic_ispanstream [ispanstream]

31.9.4.1 General [ispanstream.general]

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;explicit 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);void swap(basic_ispanstream& rhs); 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; };}

[Note 1:

Constructing an ispanstream from a string-literalincludes the termination character '\0'in the underlying spanbuf.

— _end note_]

31.9.4.2 Constructors [ispanstream.cons]

explicit basic_ispanstream(std::span<charT> s, ios_base::openmode which = ios_base::in);

Effects: Initializes the base class withbasic_istream<charT, traits>(addressof(sb))and sb withbasic_spanbuf<charT, traits>(s, which | ios_base​::​in) ([spanbuf.cons]).

basic_ispanstream(basic_ispanstream&& rhs);

Effects: Initializes the base class with std​::​move(rhs)and sb with std​::​move(rhs.sb).

Next, basic_istream<charT, traits>​::​set_rdbuf(addressof(sb)) is called to install the contained basic_spanbuf.

template<class ROS> explicit basic_ispanstream(ROS&& s)

Effects: Let sp be std​::​span<const charT>(std​::​forward<ROS>(s)).

Equivalent to:basic_ispanstream(std::span<charT>(const_cast<charT*>(sp.data()), sp.size()))

31.9.4.3 Swap [ispanstream.swap]

void swap(basic_ispanstream& rhs);

Effects: Equivalent to:basic_istream<charT, traits>::swap(rhs);sb.swap(rhs.sb);

template<class charT, class traits> void swap(basic_ispanstream<charT, traits>& x, basic_ispanstream<charT, traits>& y);

Effects: Equivalent to x.swap(y).

31.9.4.4 Member functions [ispanstream.members]

basic_spanbuf<charT, traits>* rdbuf() const noexcept;

Effects: Equivalent to:return const_cast<basic_spanbuf<charT, traits>*>(addressof(sb));

std::span<const charT> span() const noexcept;

Effects: Equivalent to: return rdbuf()->span();

void span(std::span<charT> s) noexcept;

Effects: Equivalent to rdbuf()->span(s).

template<class ROS> void span(ROS&& s) noexcept;

Effects: Let sp be std​::​span<const charT>(std​::​forward<ROS>(s)).

Equivalent to:this->span(std::span<charT>(const_cast<charT*>(sp.data()), sp.size()));