namespace std {
template<class charT, class traits = char_traits<charT>,
class Allocator = allocator<charT>>
class basic_stringbuf : public basic_streambuf<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;
using allocator_type = Allocator;
basic_stringbuf() : basic_stringbuf(ios_base::in | ios_base::out) {}
explicit basic_stringbuf(ios_base::openmode which);
explicit basic_stringbuf(
const basic_string<charT, traits, Allocator>& s,
ios_base::openmode which = ios_base::in | ios_base::out);
explicit basic_stringbuf(const Allocator& a)
: basic_stringbuf(ios_base::in | ios_base::out, a) {}
basic_stringbuf(ios_base::openmode which, const Allocator& a);
explicit basic_stringbuf(
basic_string<charT, traits, Allocator>&& s,
ios_base::openmode which = ios_base::in | ios_base::out);
template<class SAlloc>
basic_stringbuf(
const basic_string<charT, traits, SAlloc>& s, const Allocator& a)
: basic_stringbuf(s, ios_base::in | ios_base::out, a) {}
template<class SAlloc>
basic_stringbuf(
const basic_string<charT, traits, SAlloc>& s,
ios_base::openmode which, const Allocator& a);
template<class SAlloc>
explicit basic_stringbuf(
const basic_string<charT, traits, SAlloc>& s,
ios_base::openmode which = ios_base::in | ios_base::out);
basic_stringbuf(const basic_stringbuf&) = delete;
basic_stringbuf(basic_stringbuf&& rhs);
basic_stringbuf(basic_stringbuf&& rhs, const Allocator& a);
basic_stringbuf& operator=(const basic_stringbuf&) = delete;
basic_stringbuf& operator=(basic_stringbuf&& rhs);
void swap(basic_stringbuf& rhs) noexcept(see below);
allocator_type get_allocator() const noexcept;
basic_string<charT, traits, Allocator> str() const &;
template<class SAlloc>
basic_string<charT,traits,SAlloc> str(const SAlloc& sa) const;
basic_string<charT, traits, Allocator> str() &&;
basic_string_view<charT, traits> view() const noexcept;
void str(const basic_string<charT, traits, Allocator>& s);
template<class SAlloc>
void str(const basic_string<charT, traits, SAlloc>& s);
void str(basic_string<charT, traits, Allocator>&& s);
protected:
int_type underflow() override;
int_type pbackfail(int_type c = traits::eof()) override;
int_type overflow (int_type c = traits::eof()) override;
basic_streambuf<charT, traits>* setbuf(charT*, streamsize) override;
pos_type seekoff(off_type off, ios_base::seekdir way,
ios_base::openmode which
= ios_base::in | ios_base::out) override;
pos_type seekpos(pos_type sp,
ios_base::openmode which
= ios_base::in | ios_base::out) override;
private:
ios_base::openmode mode;
basic_string<charT, traits, Allocator> buf;
void init_buf_ptrs();
};
template<class charT, class traits, class Allocator>
void swap(basic_stringbuf<charT, traits, Allocator>& x,
basic_stringbuf<charT, traits, Allocator>& y) noexcept(noexcept(x.swap(y)));
}
The class
basic_stringbuf
is derived from
basic_streambuf
to associate possibly the input sequence and possibly
the output sequence with a sequence of arbitrary
characters. The sequence can be initialized from, or made available as, an object of class
basic_string.For the sake of exposition,
the maintained data and internal pointer initialization is presented here as:
ios_base::openmode mode, has
in set if the input sequence can be read, and
out set if the output sequence can be written
. basic_string<charT, traits, Allocator> buf
contains the underlying character sequence
.