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--- a/cppdraft/streambuf/assign.md
+++ b/cppdraft/streambuf/assign.md
@@ -0,0 +1,67 @@
+[streambuf.assign]
+
+# 31 Input/output library [[input.output]](./#input.output)
+
+## 31.6 Stream buffers [[stream.buffers]](stream.buffers#streambuf.assign)
+
+### 31.6.3 Class template basic_streambuf [[streambuf]](streambuf#assign)
+
+#### 31.6.3.4 Protected member functions [[streambuf.protected]](streambuf.protected#streambuf.assign)
+
+#### 31.6.3.4.1 Assignment [streambuf.assign]
+
+[ð](#lib:operator=,basic_streambuf)
+
+`basic_streambuf& operator=(const basic_streambuf& rhs);
+`
+
+[1](#1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3426)
+
+*Postconditions*: 
+
+- [(1.1)](#1.1)
+
+eback() == rhs.eback()
+
+- [(1.2)](#1.2)
+
+gptr() == rhs.gptr()
+
+- [(1.3)](#1.3)
+
+egptr() == rhs.egptr()
+
+- [(1.4)](#1.4)
+
+pbase() == rhs.pbase()
+
+- [(1.5)](#1.5)
+
+pptr() == rhs.pptr()
+
+- [(1.6)](#1.6)
+
+epptr() == rhs.epptr()
+
+- [(1.7)](#1.7)
+
+getloc() == rhs.getloc()
+
+[2](#2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3438)
+
+*Returns*: *this[.](#2.sentence-1)
+
+[ð](#lib:swap,basic_streambuf)
+
+`void swap(basic_streambuf& rhs);
+`
+
+[3](#3)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3449)
+
+*Effects*: Swaps the data members of rhs and *this[.](#3.sentence-1)
--- a/cppdraft/streambuf/buffer.md
+++ b/cppdraft/streambuf/buffer.md
@@ -0,0 +1,59 @@
+[streambuf.buffer]
+
+# 31 Input/output library [[input.output]](./#input.output)
+
+## 31.6 Stream buffers [[stream.buffers]](stream.buffers#streambuf.buffer)
+
+### 31.6.3 Class template basic_streambuf [[streambuf]](streambuf#buffer)
+
+#### 31.6.3.3 Public member functions [[streambuf.members]](streambuf.members#streambuf.buffer)
+
+#### 31.6.3.3.2 Buffer management and positioning [streambuf.buffer]
+
+[ð](#lib:pubsetbuf,basic_streambuf)
+
+`basic_streambuf* pubsetbuf(char_type* s, streamsize n);
+`
+
+[1](#1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3229)
+
+*Returns*: setbuf(s, n)[.](#1.sentence-1)
+
+[ð](#lib:pubseekoff,basic_streambuf)
+
+`pos_type pubseekoff(off_type off, ios_base::seekdir way,
+                    ios_base::openmode which
+                      = ios_base::in | ios_base::out);
+`
+
+[2](#2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3242)
+
+*Returns*: seekoff(off, way, which)[.](#2.sentence-1)
+
+[ð](#lib:pubseekpos,basic_streambuf)
+
+`pos_type pubseekpos(pos_type sp,
+                    ios_base::openmode which
+                      = ios_base::in | ios_base::out);
+`
+
+[3](#3)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3255)
+
+*Returns*: seekpos(sp, which)[.](#3.sentence-1)
+
+[ð](#lib:pubsync,basic_streambuf)
+
+`int pubsync();
+`
+
+[4](#4)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3266)
+
+*Returns*: sync()[.](#4.sentence-1)
--- a/cppdraft/streambuf/cons.md
+++ b/cppdraft/streambuf/cons.md
@@ -0,0 +1,92 @@
+[streambuf.cons]
+
+# 31 Input/output library [[input.output]](./#input.output)
+
+## 31.6 Stream buffers [[stream.buffers]](stream.buffers#streambuf.cons)
+
+### 31.6.3 Class template basic_streambuf [[streambuf]](streambuf#cons)
+
+#### 31.6.3.2 Constructors [streambuf.cons]
+
+[ð](#lib:basic_streambuf,constructor)
+
+`basic_streambuf();
+`
+
+[1](#1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3112)
+
+*Effects*: Initializes:[266](#footnote-266 "The default constructor is protected for class basic_streambuf to assure that only objects for classes derived from this class can be constructed.")
+
+- [(1.1)](#1.1)
+
+all pointer member objects to null pointers,
+
+- [(1.2)](#1.2)
+
+thegetloc() member to a copy of the global locale,locale(),
+at the time of construction[.](#1.sentence-1)
+
+[2](#2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3132)
+
+*Remarks*: Once thegetloc() member is initialized, results of calling locale member functions,
+and of members of facets so obtained, can safely be cached until the
+next time the memberimbue is called[.](#2.sentence-1)
+
+[ð](#lib:basic_streambuf,constructor_)
+
+`basic_streambuf(const basic_streambuf& rhs);
+`
+
+[3](#3)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3149)
+
+*Postconditions*: 
+
+- [(3.1)](#3.1)
+
+eback() == rhs.eback()
+
+- [(3.2)](#3.2)
+
+gptr() == rhs.gptr()
+
+- [(3.3)](#3.3)
+
+egptr() == rhs.egptr()
+
+- [(3.4)](#3.4)
+
+pbase() == rhs.pbase()
+
+- [(3.5)](#3.5)
+
+pptr() == rhs.pptr()
+
+- [(3.6)](#3.6)
+
+epptr() == rhs.epptr()
+
+- [(3.7)](#3.7)
+
+getloc() == rhs.getloc()
+
+[ð](#lib:basic_streambuf,destructor)
+
+`~basic_streambuf();
+`
+
+[4](#4)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3168)
+
+*Effects*: None[.](#4.sentence-1)
+
+[266)](#footnote-266)[266)](#footnoteref-266)
+
+The default constructor is protected for classbasic_streambuf to assure that only objects for classes
+derived from this class can be constructed[.](#footnote-266.sentence-1)
--- a/cppdraft/streambuf/general.md
+++ b/cppdraft/streambuf/general.md
@@ -0,0 +1,46 @@
+[streambuf.general]
+
+# 31 Input/output library [[input.output]](./#input.output)
+
+## 31.6 Stream buffers [[stream.buffers]](stream.buffers#streambuf.general)
+
+### 31.6.3 Class template basic_streambuf [[streambuf]](streambuf#general)
+
+#### 31.6.3.1 General [streambuf.general]
+
+[ð](#lib:basic_streambuf)
+
+namespace std {template<class charT, class traits = char_traits<charT>>class basic_streambuf {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; virtual ~basic_streambuf(); // [[streambuf.locales]](streambuf.locales "31.6.3.3.1 Locales"), locales locale pubimbue(const locale& loc);
+ locale getloc() const; // [[streambuf.buffer]](streambuf.buffer "31.6.3.3.2 Buffer management and positioning"), buffer and positioning basic_streambuf* pubsetbuf(char_type* s, streamsize n);
+ pos_type pubseekoff(off_type off, ios_base::seekdir way,
+ ios_base::openmode which = ios_base::in | ios_base::out);
+ pos_type pubseekpos(pos_type sp,
+ ios_base::openmode which = ios_base::in | ios_base::out); int pubsync(); // get and put areas// [[streambuf.pub.get]](streambuf.pub.get "31.6.3.3.3 Get area"), get area streamsize in_avail();
+ int_type snextc();
+ int_type sbumpc();
+ int_type sgetc();
+ streamsize sgetn(char_type* s, streamsize n); // [[streambuf.pub.pback]](streambuf.pub.pback "31.6.3.3.4 Putback"), putback int_type sputbackc(char_type c);
+ int_type sungetc(); // [[streambuf.pub.put]](streambuf.pub.put "31.6.3.3.5 Put area"), put area int_type sputc(char_type c);
+ streamsize sputn(const char_type* s, streamsize n); protected: basic_streambuf();
+ basic_streambuf(const basic_streambuf& rhs);
+ basic_streambuf& operator=(const basic_streambuf& rhs); void swap(basic_streambuf& rhs); // [[streambuf.get.area]](streambuf.get.area "31.6.3.4.2 Get area access"), get area access char_type* eback() const;
+ char_type* gptr() const;
+ char_type* egptr() const; void gbump(int n); void setg(char_type* gbeg, char_type* gnext, char_type* gend); // [[streambuf.put.area]](streambuf.put.area "31.6.3.4.3 Put area access"), put area access char_type* pbase() const;
+ char_type* pptr() const;
+ char_type* epptr() const; void pbump(int n); void setp(char_type* pbeg, char_type* pend); // [[streambuf.virtuals]](streambuf.virtuals "31.6.3.5 Virtual functions"), virtual functions// [[streambuf.virt.locales]](streambuf.virt.locales "31.6.3.5.1 Locales"), localesvirtual void imbue(const locale& loc); // [[streambuf.virt.buffer]](streambuf.virt.buffer "31.6.3.5.2 Buffer management and positioning"), buffer management and positioningvirtual basic_streambuf* setbuf(char_type* s, streamsize n); virtual pos_type seekoff(off_type off, ios_base::seekdir way,
+ ios_base::openmode which = ios_base::in | ios_base::out); virtual pos_type seekpos(pos_type sp,
+ ios_base::openmode which = ios_base::in | ios_base::out); virtual int sync(); // [[streambuf.virt.get]](streambuf.virt.get "31.6.3.5.3 Get area"), get areavirtual streamsize showmanyc(); virtual streamsize xsgetn(char_type* s, streamsize n); virtual int_type underflow(); virtual int_type uflow(); // [[streambuf.virt.pback]](streambuf.virt.pback "31.6.3.5.4 Putback"), putbackvirtual int_type pbackfail(int_type c = traits::eof()); // [[streambuf.virt.put]](streambuf.virt.put "31.6.3.5.5 Put area"), put areavirtual streamsize xsputn(const char_type* s, streamsize n); virtual int_type overflow(int_type c = traits::eof()); };}
+
+[1](#1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3088)
+
+The class templatebasic_streambuf serves as a base class for deriving various[*stream buffers*](#def:stream_buffers) whose objects each control two[*character sequences*](#def:character_sequences):
+
+- [(1.1)](#1.1)
+
+a character[*input sequence*](#def:input_sequence);
+
+- [(1.2)](#1.2)
+
+a character[*output sequence*](#def:output_sequence)[.](#1.sentence-1)
--- a/cppdraft/streambuf/get/area.md
+++ b/cppdraft/streambuf/get/area.md
@@ -0,0 +1,74 @@
+[streambuf.get.area]
+
+# 31 Input/output library [[input.output]](./#input.output)
+
+## 31.6 Stream buffers [[stream.buffers]](stream.buffers#streambuf.get.area)
+
+### 31.6.3 Class template basic_streambuf [[streambuf]](streambuf#get.area)
+
+#### 31.6.3.4 Protected member functions [[streambuf.protected]](streambuf.protected#streambuf.get.area)
+
+#### 31.6.3.4.2 Get area access [streambuf.get.area]
+
+[ð](#lib:eback,basic_streambuf)
+
+`char_type* eback() const;
+`
+
+[1](#1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3463)
+
+*Returns*: The beginning pointer for the input sequence[.](#1.sentence-1)
+
+[ð](#lib:gptr,basic_streambuf)
+
+`char_type* gptr() const;
+`
+
+[2](#2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3474)
+
+*Returns*: The next pointer for the input sequence[.](#2.sentence-1)
+
+[ð](#lib:egptr,basic_streambuf)
+
+`char_type* egptr() const;
+`
+
+[3](#3)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3485)
+
+*Returns*: The end pointer for the input sequence[.](#3.sentence-1)
+
+[ð](#lib:gbump,basic_streambuf)
+
+`void gbump(int n);
+`
+
+[4](#4)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3496)
+
+*Effects*: Adds n to the next pointer for the input sequence[.](#4.sentence-1)
+
+[ð](#lib:setg,basic_streambuf)
+
+`void setg(char_type* gbeg, char_type* gnext, char_type* gend);
+`
+
+[5](#5)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3507)
+
+*Preconditions*: [gbeg, gnext), [gbeg, gend), and [gnext, gend)
+are all valid ranges[.](#5.sentence-1)
+
+[6](#6)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3512)
+
+*Postconditions*: gbeg == eback(),gnext == gptr(),
+andgend == egptr() are all true[.](#6.sentence-1)
--- a/cppdraft/streambuf/locales.md
+++ b/cppdraft/streambuf/locales.md
@@ -0,0 +1,50 @@
+[streambuf.locales]
+
+# 31 Input/output library [[input.output]](./#input.output)
+
+## 31.6 Stream buffers [[stream.buffers]](stream.buffers#streambuf.locales)
+
+### 31.6.3 Class template basic_streambuf [[streambuf]](streambuf#locales)
+
+#### 31.6.3.3 Public member functions [[streambuf.members]](streambuf.members#streambuf.locales)
+
+#### 31.6.3.3.1 Locales [streambuf.locales]
+
+[ð](#lib:pubimbue,basic_streambuf)
+
+`locale pubimbue(const locale& loc);
+`
+
+[1](#1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3183)
+
+*Effects*: Callsimbue(loc)[.](#1.sentence-1)
+
+[2](#2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3188)
+
+*Postconditions*: loc == getloc()[.](#2.sentence-1)
+
+[3](#3)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3192)
+
+*Returns*: Previous value ofgetloc()[.](#3.sentence-1)
+
+[ð](#lib:getloc,basic_streambuf)
+
+`locale getloc() const;
+`
+
+[4](#4)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3204)
+
+*Returns*: Ifpubimbue() has ever been called, then the last value of loc supplied,
+otherwise the current global locale,locale(),
+in effect at the time of construction[.](#4.sentence-1)
+
+If called afterpubimbue() has been called but beforepubimbue has returned (i.e., from within the call ofimbue())
+then it returns the previous value[.](#4.sentence-2)
--- a/cppdraft/streambuf/members.md
+++ b/cppdraft/streambuf/members.md
@@ -0,0 +1,235 @@
+[streambuf.members]
+
+# 31 Input/output library [[input.output]](./#input.output)
+
+## 31.6 Stream buffers [[stream.buffers]](stream.buffers#streambuf.members)
+
+### 31.6.3 Class template basic_streambuf [[streambuf]](streambuf#members)
+
+#### 31.6.3.3 Public member functions [streambuf.members]
+
+#### [31.6.3.3.1](#streambuf.locales) Locales [[streambuf.locales]](streambuf.locales)
+
+[ð](#lib:pubimbue,basic_streambuf)
+
+`locale pubimbue(const locale& loc);
+`
+
+[1](#streambuf.locales-1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3183)
+
+*Effects*: Callsimbue(loc)[.](#streambuf.locales-1.sentence-1)
+
+[2](#streambuf.locales-2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3188)
+
+*Postconditions*: loc == getloc()[.](#streambuf.locales-2.sentence-1)
+
+[3](#streambuf.locales-3)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3192)
+
+*Returns*: Previous value ofgetloc()[.](#streambuf.locales-3.sentence-1)
+
+[ð](#lib:getloc,basic_streambuf)
+
+`locale getloc() const;
+`
+
+[4](#streambuf.locales-4)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3204)
+
+*Returns*: Ifpubimbue() has ever been called, then the last value of loc supplied,
+otherwise the current global locale,locale(),
+in effect at the time of construction[.](#streambuf.locales-4.sentence-1)
+
+If called afterpubimbue() has been called but beforepubimbue has returned (i.e., from within the call ofimbue())
+then it returns the previous value[.](#streambuf.locales-4.sentence-2)
+
+#### [31.6.3.3.2](#streambuf.buffer) Buffer management and positioning [[streambuf.buffer]](streambuf.buffer)
+
+[ð](#lib:pubsetbuf,basic_streambuf)
+
+`basic_streambuf* pubsetbuf(char_type* s, streamsize n);
+`
+
+[1](#streambuf.buffer-1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3229)
+
+*Returns*: setbuf(s, n)[.](#streambuf.buffer-1.sentence-1)
+
+[ð](#lib:pubseekoff,basic_streambuf)
+
+`pos_type pubseekoff(off_type off, ios_base::seekdir way,
+                    ios_base::openmode which
+                      = ios_base::in | ios_base::out);
+`
+
+[2](#streambuf.buffer-2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3242)
+
+*Returns*: seekoff(off, way, which)[.](#streambuf.buffer-2.sentence-1)
+
+[ð](#lib:pubseekpos,basic_streambuf)
+
+`pos_type pubseekpos(pos_type sp,
+                    ios_base::openmode which
+                      = ios_base::in | ios_base::out);
+`
+
+[3](#streambuf.buffer-3)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3255)
+
+*Returns*: seekpos(sp, which)[.](#streambuf.buffer-3.sentence-1)
+
+[ð](#lib:pubsync,basic_streambuf)
+
+`int pubsync();
+`
+
+[4](#streambuf.buffer-4)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3266)
+
+*Returns*: sync()[.](#streambuf.buffer-4.sentence-1)
+
+#### [31.6.3.3.3](#streambuf.pub.get) Get area [[streambuf.pub.get]](streambuf.pub.get)
+
+[ð](#lib:in_avail,basic_streambuf)
+
+`streamsize in_avail();
+`
+
+[1](#streambuf.pub.get-1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3279)
+
+*Returns*: If a read position is available, returnsegptr() - gptr()[.](#streambuf.pub.get-1.sentence-1)
+
+Otherwise returns[showmanyc()](filebuf.virtuals#lib:basic_streambuf,showmanyc "31.10.3.5 Overridden virtual functions [filebuf.virtuals]")[.](#streambuf.pub.get-1.sentence-2)
+
+[ð](#lib:snextc,basic_streambuf)
+
+`int_type snextc();
+`
+
+[2](#streambuf.pub.get-2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3293)
+
+*Effects*: Callssbumpc()[.](#streambuf.pub.get-2.sentence-1)
+
+[3](#streambuf.pub.get-3)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3298)
+
+*Returns*: If that function returnstraits::eof(),
+returnstraits::eof()[.](#streambuf.pub.get-3.sentence-1)
+
+Otherwise, returnssgetc()[.](#streambuf.pub.get-3.sentence-2)
+
+[ð](#lib:sbumpc,basic_streambuf)
+
+`int_type sbumpc();
+`
+
+[4](#streambuf.pub.get-4)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3314)
+
+*Effects*: If the input sequence read position is not available,
+returnsuflow()[.](#streambuf.pub.get-4.sentence-1)
+
+Otherwise, returnstraits::to_int_type(*gptr()) and increments the next pointer for the input sequence[.](#streambuf.pub.get-4.sentence-2)
+
+[ð](#lib:sgetc,basic_streambuf)
+
+`int_type sgetc();
+`
+
+[5](#streambuf.pub.get-5)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3330)
+
+*Returns*: If the input sequence read position is not available,
+returnsunderflow()[.](#streambuf.pub.get-5.sentence-1)
+
+Otherwise, returnstraits::to_int_type(*gptr())[.](#streambuf.pub.get-5.sentence-2)
+
+[ð](#lib:sgetn,basic_streambuf)
+
+`streamsize sgetn(char_type* s, streamsize n);
+`
+
+[6](#streambuf.pub.get-6)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3345)
+
+*Returns*: xsgetn(s, n)[.](#streambuf.pub.get-6.sentence-1)
+
+#### [31.6.3.3.4](#streambuf.pub.pback) Putback [[streambuf.pub.pback]](streambuf.pub.pback)
+
+[ð](#lib:sputbackc,basic_streambuf)
+
+`int_type sputbackc(char_type c);
+`
+
+[1](#streambuf.pub.pback-1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3358)
+
+*Effects*: If the input sequence putback position is not available, or
+iftraits::eq(c, gptr()[-1]) is false, returnspbackfail(traits::to_int_type(c))[.](#streambuf.pub.pback-1.sentence-1)
+
+Otherwise, decrements the next pointer for the input sequence and
+returnstraits::to_int_type(*gptr())[.](#streambuf.pub.pback-1.sentence-2)
+
+[ð](#lib:sungetc,basic_streambuf)
+
+`int_type sungetc();
+`
+
+[2](#streambuf.pub.pback-2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3376)
+
+*Effects*: If the input sequence putback position is not available,
+returnspbackfail()[.](#streambuf.pub.pback-2.sentence-1)
+
+Otherwise, decrements the next pointer for the input sequence and
+returnstraits::to_int_type(*gptr())[.](#streambuf.pub.pback-2.sentence-2)
+
+#### [31.6.3.3.5](#streambuf.pub.put) Put area [[streambuf.pub.put]](streambuf.pub.put)
+
+[ð](#lib:sputc,basic_streambuf)
+
+`int_type sputc(char_type c);
+`
+
+[1](#streambuf.pub.put-1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3394)
+
+*Effects*: If the output sequence write position is not available,
+returnsoverflow(traits::to_int_type(c))[.](#streambuf.pub.put-1.sentence-1)
+
+Otherwise, stores c at the next pointer for the output sequence,
+increments the pointer, and
+returnstraits::to_int_type(c)[.](#streambuf.pub.put-1.sentence-2)
+
+[ð](#lib:sputn,basic_streambuf)
+
+`streamsize sputn(const char_type* s, streamsize n);
+`
+
+[2](#streambuf.pub.put-2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3411)
+
+*Returns*: xsputn(s, n)[.](#streambuf.pub.put-2.sentence-1)
--- a/cppdraft/streambuf/protected.md
+++ b/cppdraft/streambuf/protected.md
@@ -0,0 +1,196 @@
+[streambuf.protected]
+
+# 31 Input/output library [[input.output]](./#input.output)
+
+## 31.6 Stream buffers [[stream.buffers]](stream.buffers#streambuf.protected)
+
+### 31.6.3 Class template basic_streambuf [[streambuf]](streambuf#protected)
+
+#### 31.6.3.4 Protected member functions [streambuf.protected]
+
+#### [31.6.3.4.1](#streambuf.assign) Assignment [[streambuf.assign]](streambuf.assign)
+
+[ð](#lib:operator=,basic_streambuf)
+
+`basic_streambuf& operator=(const basic_streambuf& rhs);
+`
+
+[1](#streambuf.assign-1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3426)
+
+*Postconditions*: 
+
+- [(1.1)](#streambuf.assign-1.1)
+
+eback() == rhs.eback()
+
+- [(1.2)](#streambuf.assign-1.2)
+
+gptr() == rhs.gptr()
+
+- [(1.3)](#streambuf.assign-1.3)
+
+egptr() == rhs.egptr()
+
+- [(1.4)](#streambuf.assign-1.4)
+
+pbase() == rhs.pbase()
+
+- [(1.5)](#streambuf.assign-1.5)
+
+pptr() == rhs.pptr()
+
+- [(1.6)](#streambuf.assign-1.6)
+
+epptr() == rhs.epptr()
+
+- [(1.7)](#streambuf.assign-1.7)
+
+getloc() == rhs.getloc()
+
+[2](#streambuf.assign-2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3438)
+
+*Returns*: *this[.](#streambuf.assign-2.sentence-1)
+
+[ð](#lib:swap,basic_streambuf)
+
+`void swap(basic_streambuf& rhs);
+`
+
+[3](#streambuf.assign-3)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3449)
+
+*Effects*: Swaps the data members of rhs and *this[.](#streambuf.assign-3.sentence-1)
+
+#### [31.6.3.4.2](#streambuf.get.area) Get area access [[streambuf.get.area]](streambuf.get.area)
+
+[ð](#lib:eback,basic_streambuf)
+
+`char_type* eback() const;
+`
+
+[1](#streambuf.get.area-1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3463)
+
+*Returns*: The beginning pointer for the input sequence[.](#streambuf.get.area-1.sentence-1)
+
+[ð](#lib:gptr,basic_streambuf)
+
+`char_type* gptr() const;
+`
+
+[2](#streambuf.get.area-2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3474)
+
+*Returns*: The next pointer for the input sequence[.](#streambuf.get.area-2.sentence-1)
+
+[ð](#lib:egptr,basic_streambuf)
+
+`char_type* egptr() const;
+`
+
+[3](#streambuf.get.area-3)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3485)
+
+*Returns*: The end pointer for the input sequence[.](#streambuf.get.area-3.sentence-1)
+
+[ð](#lib:gbump,basic_streambuf)
+
+`void gbump(int n);
+`
+
+[4](#streambuf.get.area-4)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3496)
+
+*Effects*: Adds n to the next pointer for the input sequence[.](#streambuf.get.area-4.sentence-1)
+
+[ð](#lib:setg,basic_streambuf)
+
+`void setg(char_type* gbeg, char_type* gnext, char_type* gend);
+`
+
+[5](#streambuf.get.area-5)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3507)
+
+*Preconditions*: [gbeg, gnext), [gbeg, gend), and [gnext, gend)
+are all valid ranges[.](#streambuf.get.area-5.sentence-1)
+
+[6](#streambuf.get.area-6)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3512)
+
+*Postconditions*: gbeg == eback(),gnext == gptr(),
+andgend == egptr() are all true[.](#streambuf.get.area-6.sentence-1)
+
+#### [31.6.3.4.3](#streambuf.put.area) Put area access [[streambuf.put.area]](streambuf.put.area)
+
+[ð](#lib:pbase,basic_streambuf)
+
+`char_type* pbase() const;
+`
+
+[1](#streambuf.put.area-1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3528)
+
+*Returns*: The beginning pointer for the output sequence[.](#streambuf.put.area-1.sentence-1)
+
+[ð](#lib:pptr,basic_streambuf)
+
+`char_type* pptr() const;
+`
+
+[2](#streambuf.put.area-2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3539)
+
+*Returns*: The next pointer for the output sequence[.](#streambuf.put.area-2.sentence-1)
+
+[ð](#lib:epptr,basic_streambuf)
+
+`char_type* epptr() const;
+`
+
+[3](#streambuf.put.area-3)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3550)
+
+*Returns*: The end pointer for the output sequence[.](#streambuf.put.area-3.sentence-1)
+
+[ð](#lib:pbump,basic_streambuf)
+
+`void pbump(int n);
+`
+
+[4](#streambuf.put.area-4)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3561)
+
+*Effects*: Adds n to the next pointer for the output sequence[.](#streambuf.put.area-4.sentence-1)
+
+[ð](#lib:setp,basic_streambuf)
+
+`void setp(char_type* pbeg, char_type* pend);
+`
+
+[5](#streambuf.put.area-5)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3572)
+
+*Preconditions*: [pbeg, pend) is a valid range[.](#streambuf.put.area-5.sentence-1)
+
+[6](#streambuf.put.area-6)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3576)
+
+*Postconditions*: pbeg == pbase(),pbeg == pptr(),
+andpend == epptr() are all true[.](#streambuf.put.area-6.sentence-1)
--- a/cppdraft/streambuf/pub/get.md
+++ b/cppdraft/streambuf/pub/get.md
@@ -0,0 +1,83 @@
+[streambuf.pub.get]
+
+# 31 Input/output library [[input.output]](./#input.output)
+
+## 31.6 Stream buffers [[stream.buffers]](stream.buffers#streambuf.pub.get)
+
+### 31.6.3 Class template basic_streambuf [[streambuf]](streambuf#pub.get)
+
+#### 31.6.3.3 Public member functions [[streambuf.members]](streambuf.members#streambuf.pub.get)
+
+#### 31.6.3.3.3 Get area [streambuf.pub.get]
+
+[ð](#lib:in_avail,basic_streambuf)
+
+`streamsize in_avail();
+`
+
+[1](#1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3279)
+
+*Returns*: If a read position is available, returnsegptr() - gptr()[.](#1.sentence-1)
+
+Otherwise returns[showmanyc()](filebuf.virtuals#lib:basic_streambuf,showmanyc "31.10.3.5 Overridden virtual functions [filebuf.virtuals]")[.](#1.sentence-2)
+
+[ð](#lib:snextc,basic_streambuf)
+
+`int_type snextc();
+`
+
+[2](#2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3293)
+
+*Effects*: Callssbumpc()[.](#2.sentence-1)
+
+[3](#3)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3298)
+
+*Returns*: If that function returnstraits::eof(),
+returnstraits::eof()[.](#3.sentence-1)
+
+Otherwise, returnssgetc()[.](#3.sentence-2)
+
+[ð](#lib:sbumpc,basic_streambuf)
+
+`int_type sbumpc();
+`
+
+[4](#4)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3314)
+
+*Effects*: If the input sequence read position is not available,
+returnsuflow()[.](#4.sentence-1)
+
+Otherwise, returnstraits::to_int_type(*gptr()) and increments the next pointer for the input sequence[.](#4.sentence-2)
+
+[ð](#lib:sgetc,basic_streambuf)
+
+`int_type sgetc();
+`
+
+[5](#5)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3330)
+
+*Returns*: If the input sequence read position is not available,
+returnsunderflow()[.](#5.sentence-1)
+
+Otherwise, returnstraits::to_int_type(*gptr())[.](#5.sentence-2)
+
+[ð](#lib:sgetn,basic_streambuf)
+
+`streamsize sgetn(char_type* s, streamsize n);
+`
+
+[6](#6)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3345)
+
+*Returns*: xsgetn(s, n)[.](#6.sentence-1)
--- a/cppdraft/streambuf/pub/pback.md
+++ b/cppdraft/streambuf/pub/pback.md
@@ -0,0 +1,41 @@
+[streambuf.pub.pback]
+
+# 31 Input/output library [[input.output]](./#input.output)
+
+## 31.6 Stream buffers [[stream.buffers]](stream.buffers#streambuf.pub.pback)
+
+### 31.6.3 Class template basic_streambuf [[streambuf]](streambuf#pub.pback)
+
+#### 31.6.3.3 Public member functions [[streambuf.members]](streambuf.members#streambuf.pub.pback)
+
+#### 31.6.3.3.4 Putback [streambuf.pub.pback]
+
+[ð](#lib:sputbackc,basic_streambuf)
+
+`int_type sputbackc(char_type c);
+`
+
+[1](#1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3358)
+
+*Effects*: If the input sequence putback position is not available, or
+iftraits::eq(c, gptr()[-1]) is false, returnspbackfail(traits::to_int_type(c))[.](#1.sentence-1)
+
+Otherwise, decrements the next pointer for the input sequence and
+returnstraits::to_int_type(*gptr())[.](#1.sentence-2)
+
+[ð](#lib:sungetc,basic_streambuf)
+
+`int_type sungetc();
+`
+
+[2](#2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3376)
+
+*Effects*: If the input sequence putback position is not available,
+returnspbackfail()[.](#2.sentence-1)
+
+Otherwise, decrements the next pointer for the input sequence and
+returnstraits::to_int_type(*gptr())[.](#2.sentence-2)
--- a/cppdraft/streambuf/pub/put.md
+++ b/cppdraft/streambuf/pub/put.md
@@ -0,0 +1,38 @@
+[streambuf.pub.put]
+
+# 31 Input/output library [[input.output]](./#input.output)
+
+## 31.6 Stream buffers [[stream.buffers]](stream.buffers#streambuf.pub.put)
+
+### 31.6.3 Class template basic_streambuf [[streambuf]](streambuf#pub.put)
+
+#### 31.6.3.3 Public member functions [[streambuf.members]](streambuf.members#streambuf.pub.put)
+
+#### 31.6.3.3.5 Put area [streambuf.pub.put]
+
+[ð](#lib:sputc,basic_streambuf)
+
+`int_type sputc(char_type c);
+`
+
+[1](#1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3394)
+
+*Effects*: If the output sequence write position is not available,
+returnsoverflow(traits::to_int_type(c))[.](#1.sentence-1)
+
+Otherwise, stores c at the next pointer for the output sequence,
+increments the pointer, and
+returnstraits::to_int_type(c)[.](#1.sentence-2)
+
+[ð](#lib:sputn,basic_streambuf)
+
+`streamsize sputn(const char_type* s, streamsize n);
+`
+
+[2](#2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3411)
+
+*Returns*: xsputn(s, n)[.](#2.sentence-1)
--- a/cppdraft/streambuf/put/area.md
+++ b/cppdraft/streambuf/put/area.md
@@ -0,0 +1,73 @@
+[streambuf.put.area]
+
+# 31 Input/output library [[input.output]](./#input.output)
+
+## 31.6 Stream buffers [[stream.buffers]](stream.buffers#streambuf.put.area)
+
+### 31.6.3 Class template basic_streambuf [[streambuf]](streambuf#put.area)
+
+#### 31.6.3.4 Protected member functions [[streambuf.protected]](streambuf.protected#streambuf.put.area)
+
+#### 31.6.3.4.3 Put area access [streambuf.put.area]
+
+[ð](#lib:pbase,basic_streambuf)
+
+`char_type* pbase() const;
+`
+
+[1](#1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3528)
+
+*Returns*: The beginning pointer for the output sequence[.](#1.sentence-1)
+
+[ð](#lib:pptr,basic_streambuf)
+
+`char_type* pptr() const;
+`
+
+[2](#2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3539)
+
+*Returns*: The next pointer for the output sequence[.](#2.sentence-1)
+
+[ð](#lib:epptr,basic_streambuf)
+
+`char_type* epptr() const;
+`
+
+[3](#3)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3550)
+
+*Returns*: The end pointer for the output sequence[.](#3.sentence-1)
+
+[ð](#lib:pbump,basic_streambuf)
+
+`void pbump(int n);
+`
+
+[4](#4)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3561)
+
+*Effects*: Adds n to the next pointer for the output sequence[.](#4.sentence-1)
+
+[ð](#lib:setp,basic_streambuf)
+
+`void setp(char_type* pbeg, char_type* pend);
+`
+
+[5](#5)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3572)
+
+*Preconditions*: [pbeg, pend) is a valid range[.](#5.sentence-1)
+
+[6](#6)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3576)
+
+*Postconditions*: pbeg == pbase(),pbeg == pptr(),
+andpend == epptr() are all true[.](#6.sentence-1)
--- a/cppdraft/streambuf/reqts.md
+++ b/cppdraft/streambuf/reqts.md
@@ -0,0 +1,109 @@
+[streambuf.reqts]
+
+# 31 Input/output library [[input.output]](./#input.output)
+
+## 31.6 Stream buffers [[stream.buffers]](stream.buffers#streambuf.reqts)
+
+### 31.6.2 Stream buffer requirements [streambuf.reqts]
+
+[1](#1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2891)
+
+Stream buffers can impose various constraints on the sequences they control[.](#1.sentence-1)
+
+Some constraints are:
+
+- [(1.1)](#1.1)
+
+  The controlled input sequence can be not readable[.](#1.1.sentence-1)
+
+- [(1.2)](#1.2)
+
+  The controlled output sequence can be not writable[.](#1.2.sentence-1)
+
+- [(1.3)](#1.3)
+
+  The controlled sequences can be associated with the contents of other
+representations for character sequences, such as external files[.](#1.3.sentence-1)
+
+- [(1.4)](#1.4)
+
+  The controlled sequences can support operations*directly* to or from associated sequences[.](#1.4.sentence-1)
+
+- [(1.5)](#1.5)
+
+  The controlled sequences can impose limitations on how the program can
+read characters from a sequence,
+write characters to a sequence,
+put characters back into an input sequence, or
+alter the stream position[.](#1.5.sentence-1)
+
+[2](#2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2914)
+
+Each sequence is characterized by three pointers which, if non-null,
+all point into the samecharT array object[.](#2.sentence-1)
+
+The array object represents, at any moment,
+a (sub)sequence of characters from the sequence[.](#2.sentence-2)
+
+Operations performed on a sequence alter the values stored in these pointers,
+perform reads and writes directly to or from associated sequences, and
+alter âthe stream positionâ and conversion state as needed to
+maintain this subsequence relationship[.](#2.sentence-3)
+
+The three pointers are:
+
+- [(2.1)](#2.1)
+
+the[*beginning pointer*](#def:beginning_pointer),
+or lowest element address in the array
+(called xbeg here);
+
+- [(2.2)](#2.2)
+
+the[*next pointer*](#def:next_pointer),
+or next element address that is a current
+candidate for reading or writing (called xnext here);
+
+- [(2.3)](#2.3)
+
+the[*end pointer*](#def:end_pointer),
+or first element address beyond the end of
+the array (called xend here)[.](#2.sentence-4)
+
+[3](#3)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2944)
+
+The following semantic constraints shall always apply for any set of
+three pointers for a sequence, using the pointer names given immediately above:
+
+- [(3.1)](#3.1)
+
+  If xnext is not a null pointer, thenxbeg and xend shall also be non-null pointers
+into the samecharT array, as described above; otherwise, xbeg andxend shall also be null[.](#3.1.sentence-1)
+
+- [(3.2)](#3.2)
+
+  If xnext is not a null pointer andxnext < xend for an output sequence, then a[*write position*](#def:write_position) is available[.](#3.2.sentence-1)
+  In this case,*xnext shall be assignable as the
+next element to write
+(to put, or to store a character value, into the sequence)[.](#3.2.sentence-2)
+
+- [(3.3)](#3.3)
+
+  If xnext is not a null pointer andxbeg < xnext for an input sequence,
+then a[*putback position*](#def:putback_position) is available[.](#3.3.sentence-1)
+  In this case,xnext[-1] shall have a defined value and is the next (preceding) element
+to store a character that is put back into the input sequence[.](#3.3.sentence-2)
+
+- [(3.4)](#3.4)
+
+  If xnext is not a null pointer andxnext < xend for an input sequence,
+then a[*read position*](#def:read_position) is available[.](#3.4.sentence-1)
+  In this case,*xnext shall have a defined value
+and is the next element to read
+(to get, or to obtain a character value, from the sequence)[.](#3.4.sentence-2)
--- a/cppdraft/streambuf/syn.md
+++ b/cppdraft/streambuf/syn.md
@@ -0,0 +1,17 @@
+[streambuf.syn]
+
+# 31 Input/output library [[input.output]](./#input.output)
+
+## 31.6 Stream buffers [[stream.buffers]](stream.buffers#streambuf.syn)
+
+### 31.6.1 Header <streambuf> synopsis [streambuf.syn]
+
+[ð](#header:%3cstreambuf%3e)
+
+namespace std {// [[streambuf]](streambuf "31.6.3 Class template basic_streambuf"), class template basic_streambuftemplate<class charT, class traits = char_traits<charT>>class basic_streambuf; using streambuf = basic_streambuf<char>; using wstreambuf = basic_streambuf<wchar_t>;}
+
+[1](#1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L2884)
+
+The header [<streambuf>](#header:%3cstreambuf%3e "31.6.1 Header <streambuf> synopsis [streambuf.syn]") defines types that control input from and output to*character* sequences[.](#1.sentence-1)
--- a/cppdraft/streambuf/virt/buffer.md
+++ b/cppdraft/streambuf/virt/buffer.md
@@ -0,0 +1,102 @@
+[streambuf.virt.buffer]
+
+# 31 Input/output library [[input.output]](./#input.output)
+
+## 31.6 Stream buffers [[stream.buffers]](stream.buffers#streambuf.virt.buffer)
+
+### 31.6.3 Class template basic_streambuf [[streambuf]](streambuf#virt.buffer)
+
+#### 31.6.3.5 Virtual functions [[streambuf.virtuals]](streambuf.virtuals#streambuf.virt.buffer)
+
+#### 31.6.3.5.2 Buffer management and positioning [streambuf.virt.buffer]
+
+[ð](#lib:setbuf,basic_streambuf)
+
+`basic_streambuf* setbuf(char_type* s, streamsize n);
+`
+
+[1](#1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3619)
+
+*Effects*: Influences stream buffering in a way that is defined separately for each class
+derived frombasic_streambuf in this Clause ([[stringbuf.virtuals]](stringbuf.virtuals "31.8.2.5 Overridden virtual functions"), [[filebuf.virtuals]](filebuf.virtuals "31.10.3.5 Overridden virtual functions"))[.](#1.sentence-1)
+
+[2](#2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3626)
+
+*Default behavior*: Does nothing[.](#2.sentence-1)
+
+Returnsthis[.](#2.sentence-2)
+
+[ð](#lib:seekoff,basic_streambuf)
+
+`pos_type seekoff(off_type off, ios_base::seekdir way,
+                 ios_base::openmode which
+                   = ios_base::in | ios_base::out);
+`
+
+[3](#3)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3641)
+
+*Effects*: Alters the stream positions within one or more of
+the controlled sequences in a way that is defined separately for each class
+derived frombasic_streambuf in this Clause ([[stringbuf.virtuals]](stringbuf.virtuals "31.8.2.5 Overridden virtual functions"), [[filebuf.virtuals]](filebuf.virtuals "31.10.3.5 Overridden virtual functions"))[.](#3.sentence-1)
+
+[4](#4)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3649)
+
+*Default behavior*: Returnspos_type(off_type(-1))[.](#4.sentence-1)
+
+[ð](#lib:seekpos,basic_streambuf)
+
+`pos_type seekpos(pos_type sp,
+                 ios_base::openmode which
+                   = ios_base::in | ios_base::out);
+`
+
+[5](#5)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3663)
+
+*Effects*: Alters the stream positions within one or more of
+the controlled sequences in a way that is defined separately for each class
+derived frombasic_streambuf in this Clause ([[stringbuf]](stringbuf "31.8.2 Class template basic_stringbuf"), [[filebuf]](filebuf "31.10.3 Class template basic_filebuf"))[.](#5.sentence-1)
+
+[6](#6)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3671)
+
+*Default behavior*: Returnspos_type(off_type(-1))[.](#6.sentence-1)
+
+[ð](#lib:sync,basic_streambuf)
+
+`int sync();
+`
+
+[7](#7)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3683)
+
+*Effects*: Synchronizes the controlled sequences with the arrays[.](#7.sentence-1)
+
+That is, ifpbase() is non-null the characters betweenpbase() andpptr() are written to the controlled sequence[.](#7.sentence-2)
+
+The pointers may then be reset as appropriate[.](#7.sentence-3)
+
+[8](#8)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3695)
+
+*Returns*: -1 on failure[.](#8.sentence-1)
+
+What constitutes failure is determined by each derived class ([[filebuf.virtuals]](filebuf.virtuals "31.10.3.5 Overridden virtual functions"))[.](#8.sentence-2)
+
+[9](#9)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3700)
+
+*Default behavior*: Returns zero[.](#9.sentence-1)
--- a/cppdraft/streambuf/virt/get.md
+++ b/cppdraft/streambuf/virt/get.md
@@ -0,0 +1,204 @@
+[streambuf.virt.get]
+
+# 31 Input/output library [[input.output]](./#input.output)
+
+## 31.6 Stream buffers [[stream.buffers]](stream.buffers#streambuf.virt.get)
+
+### 31.6.3 Class template basic_streambuf [[streambuf]](streambuf#virt.get)
+
+#### 31.6.3.5 Virtual functions [[streambuf.virtuals]](streambuf.virtuals#streambuf.virt.get)
+
+#### 31.6.3.5.3 Get area [streambuf.virt.get]
+
+[ð](#lib:showmanyc,basic_streambuf)
+
+`streamsize showmanyc();[267](#footnote-267 "The morphemes of showmanyc are âes-how-many-seeâ, not âshow-manicâ.")
+`
+
+[1](#1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3716)
+
+*Returns*: An estimate of the number of
+characters available in the sequence, or â1[.](#1.sentence-1)
+
+If it returns
+a positive value, then successive calls tounderflow() will not returntraits::eof() until at least that number of characters have been
+extracted from the stream[.](#1.sentence-2)
+
+Ifshowmanyc() returns â1, then calls tounderflow() oruflow() will fail[.](#1.sentence-3)[268](#footnote-268 "underflow or uflow can fail by throwing an exception prematurely. The intention is not only that the calls will not return eof() but that they will return âimmediatelyâ.")
+
+[2](#2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3744)
+
+*Default behavior*: Returns zero[.](#2.sentence-1)
+
+[3](#3)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3748)
+
+*Remarks*: Usestraits::eof()[.](#3.sentence-1)
+
+[ð](#lib:xsgetn,basic_streambuf)
+
+`streamsize xsgetn(char_type* s, streamsize n);
+`
+
+[4](#4)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3760)
+
+*Effects*: Assigns up to n characters to successive elements of
+the array whose first element is designated by s[.](#4.sentence-1)
+
+The characters assigned are read from the input sequence as if
+by repeated calls tosbumpc()[.](#4.sentence-2)
+
+Assigning stops when either n characters
+have been assigned or a call tosbumpc() would returntraits::eof()[.](#4.sentence-3)
+
+[5](#5)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3773)
+
+*Returns*: The number of characters assigned[.](#5.sentence-1)[269](#footnote-269 "Classes derived from basic_streambuf can provide more efficient ways to implement xsgetn() and xsputn() by overriding these definitions from the base class.")
+
+[6](#6)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3786)
+
+*Remarks*: Usestraits::eof()[.](#6.sentence-1)
+
+[ð](#lib:underflow,basic_streambuf)
+
+`int_type underflow();
+`
+
+[7](#7)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3798)
+
+The[*pending sequence*](#def:pending_sequence) of characters is defined as the concatenation of
+
+- [(7.1)](#7.1)
+
+the empty sequence if gptr() is null, otherwise the
+characters in
+[gptr(), egptr()),
+followed by
+
+- [(7.2)](#7.2)
+
+some (possibly empty) sequence of characters read from the input sequence[.](#7.sentence-1)
+
+[8](#8)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3811)
+
+The[*result character*](#def:result_character) is
+the first character of the pending sequence if it is non-empty,
+otherwise
+the next character that would be read from the input sequence[.](#8.sentence-1)
+
+[9](#9)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3819)
+
+The[*backup sequence*](#def:backup_sequence) is the empty sequence if eback() is null, otherwise the
+characters in
+[eback(), gptr())[.](#9.sentence-1)
+
+[10](#10)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3826)
+
+*Effects*: The function sets up thegptr() andegptr() such that
+if the pending sequence is non-empty, thenegptr() is non-null and
+the characters in [gptr(), egptr()) are
+the characters in the pending sequence,
+otherwise
+either gptr() is null orgptr() == egptr()[.](#10.sentence-1)
+
+[11](#11)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3843)
+
+Ifeback() andgptr() are non-null then the function is not constrained as to their contents, but the âusual backup conditionâ is that either
+
+- [(11.1)](#11.1)
+
+the backup sequence contains at leastgptr() - eback() characters, in which case the characters in
+[eback(), gptr())
+agree with the lastgptr() - eback() characters of the backup sequence, or
+
+- [(11.2)](#11.2)
+
+the characters in [gptr() - n, gptr())
+agree with the backup sequence (where n is the length of the backup sequence)[.](#11.sentence-1)
+
+[12](#12)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3863)
+
+*Returns*: traits::to_int_type(c),
+where c is the first*character* of the[*pending sequence*](#def:pending_sequence),
+without moving the input sequence position past it[.](#12.sentence-1)
+
+If the pending sequence is null then the function returnstraits::eof() to indicate failure[.](#12.sentence-2)
+
+[13](#13)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3875)
+
+*Default behavior*: Returnstraits::eof()[.](#13.sentence-1)
+
+[14](#14)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3880)
+
+*Remarks*: The public members ofbasic_streambuf call this virtual function only ifgptr() is null orgptr() >= egptr()[.](#14.sentence-1)
+
+[ð](#lib:uflow,basic_streambuf)
+
+`int_type uflow();
+`
+
+[15](#15)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3896)
+
+*Preconditions*: The constraints are the same as forunderflow(),
+except that the result character is transferred from the pending
+sequence to the backup sequence, and the pending sequence is not empty before the transfer[.](#15.sentence-1)
+
+[16](#16)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3903)
+
+*Default behavior*: Callsunderflow()[.](#16.sentence-1)
+
+Ifunderflow() returnstraits::eof(),
+returnstraits::eof()[.](#16.sentence-2)
+
+Otherwise, returns the value oftraits::to_int_type(*gptr()) and increments the value of the next pointer for the input sequence[.](#16.sentence-3)
+
+[17](#17)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3917)
+
+*Returns*: traits::eof() to indicate failure[.](#17.sentence-1)
+
+[267)](#footnote-267)[267)](#footnoteref-267)
+
+The morphemes of showmanyc are âes-how-many-seeâ, not âshow-manicâ[.](#footnote-267.sentence-1)
+
+[268)](#footnote-268)[268)](#footnoteref-268)
+
+underflow oruflow can fail by throwing an exception prematurely[.](#footnote-268.sentence-1)
+
+The intention is not only that the calls will not returneof() but that they will return âimmediatelyâ[.](#footnote-268.sentence-2)
+
+[269)](#footnote-269)[269)](#footnoteref-269)
+
+Classes derived frombasic_streambuf can provide more efficient ways to implementxsgetn() andxsputn() by overriding these definitions from the base class[.](#footnote-269.sentence-1)
--- a/cppdraft/streambuf/virt/locales.md
+++ b/cppdraft/streambuf/virt/locales.md
@@ -0,0 +1,39 @@
+[streambuf.virt.locales]
+
+# 31 Input/output library [[input.output]](./#input.output)
+
+## 31.6 Stream buffers [[stream.buffers]](stream.buffers#streambuf.virt.locales)
+
+### 31.6.3 Class template basic_streambuf [[streambuf]](streambuf#virt.locales)
+
+#### 31.6.3.5 Virtual functions [[streambuf.virtuals]](streambuf.virtuals#streambuf.virt.locales)
+
+#### 31.6.3.5.1 Locales [streambuf.virt.locales]
+
+[ð](#lib:imbue,basic_streambuf)
+
+`void imbue(const locale&);
+`
+
+[1](#1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3594)
+
+*Effects*: Change any translations based on locale[.](#1.sentence-1)
+
+[2](#2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3598)
+
+*Remarks*: Allows the derived class to be informed of changes in locale at the
+time they occur[.](#2.sentence-1)
+
+Between invocations of this function a class derived
+from streambuf can safely cache results of calls to locale functions
+and to members of facets so obtained[.](#2.sentence-2)
+
+[3](#3)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3606)
+
+*Default behavior*: Does nothing[.](#3.sentence-1)
--- a/cppdraft/streambuf/virt/pback.md
+++ b/cppdraft/streambuf/virt/pback.md
@@ -0,0 +1,72 @@
+[streambuf.virt.pback]
+
+# 31 Input/output library [[input.output]](./#input.output)
+
+## 31.6 Stream buffers [[stream.buffers]](stream.buffers#streambuf.virt.pback)
+
+### 31.6.3 Class template basic_streambuf [[streambuf]](streambuf#virt.pback)
+
+#### 31.6.3.5 Virtual functions [[streambuf.virtuals]](streambuf.virtuals#streambuf.virt.pback)
+
+#### 31.6.3.5.4 Putback [streambuf.virt.pback]
+
+[ð](#lib:pbackfail,basic_streambuf)
+
+`int_type pbackfail(int_type c = traits::eof());
+`
+
+[1](#1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3931)
+
+The[*pending sequence*](#def:pending_sequence) is defined as forunderflow(),
+with the modifications that
+
+- [(1.1)](#1.1)
+
+  Iftraits::eq_int_type(c, traits::eof()) returnstrue,
+then the input sequence is backed up one character before the pending sequence is determined[.](#1.1.sentence-1)
+
+- [(1.2)](#1.2)
+
+  Iftraits::eq_int_type(c, traits::eof()) returns false, then c is prepended[.](#1.2.sentence-1)
+  Whether the input sequence is backed up or modified in any other way is unspecified[.](#1.2.sentence-2)
+
+[2](#2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3951)
+
+*Postconditions*: On return, the constraints ofgptr(),eback(),
+andpptr() are the same as forunderflow()[.](#2.sentence-1)
+
+[3](#3)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3961)
+
+*Returns*: traits::eof() to indicate failure[.](#3.sentence-1)
+
+Failure may occur because the input sequence could not be backed up, or if for some
+other reason the pointers cannot be set consistent with the constraints[.](#3.sentence-2)
+
+pbackfail() is called only when put back has really failed[.](#3.sentence-3)
+
+[4](#4)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3970)
+
+Returns some value other thantraits::eof() to indicate success[.](#4.sentence-1)
+
+[5](#5)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3975)
+
+*Default behavior*: Returnstraits::eof()[.](#5.sentence-1)
+
+[6](#6)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3980)
+
+*Remarks*: The public functions ofbasic_streambuf call this virtual function only whengptr() is null,gptr() == eback(),
+ortraits::eq(traits::to_char_type(c), gptr()[-1]) returnsfalse[.](#6.sentence-1)
+
+Other calls shall also satisfy that constraint[.](#6.sentence-2)
--- a/cppdraft/streambuf/virt/put.md
+++ b/cppdraft/streambuf/virt/put.md
@@ -0,0 +1,121 @@
+[streambuf.virt.put]
+
+# 31 Input/output library [[input.output]](./#input.output)
+
+## 31.6 Stream buffers [[stream.buffers]](stream.buffers#streambuf.virt.put)
+
+### 31.6.3 Class template basic_streambuf [[streambuf]](streambuf#virt.put)
+
+#### 31.6.3.5 Virtual functions [[streambuf.virtuals]](streambuf.virtuals#streambuf.virt.put)
+
+#### 31.6.3.5.5 Put area [streambuf.virt.put]
+
+[ð](#lib:xsputn,basic_streambuf)
+
+`streamsize xsputn(const char_type* s, streamsize n);
+`
+
+[1](#1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L4003)
+
+*Effects*: Writes up to n characters to the output sequence as if
+by repeated calls tosputc(c)[.](#1.sentence-1)
+
+The characters written are obtained from successive elements of
+the array whose first element is designated by s[.](#1.sentence-2)
+
+Writing stops when either n characters have been written or
+a call tosputc(c) would returntraits::eof()[.](#1.sentence-3)
+
+It is unspecified whether the function calls overflow() when pptr() == epptr() becomes true or whether it achieves the same effects by other means[.](#1.sentence-4)
+
+[2](#2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L4017)
+
+*Returns*: The number of characters written[.](#2.sentence-1)
+
+[ð](#lib:overflow,basic_streambuf)
+
+`int_type overflow(int_type c = traits::eof());
+`
+
+[3](#3)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L4028)
+
+*Effects*: Consumes some initial subsequence of the characters of the[*pending sequence*](#def:pending_sequence)[.](#3.sentence-1)
+
+The pending sequence is defined as the concatenation of
+
+- [(3.1)](#3.1)
+
+the empty sequence if pbase() is null, otherwise thepptr() - pbase() characters beginning atpbase(), followed by
+
+- [(3.2)](#3.2)
+
+the empty sequence
+iftraits::eq_int_type(c, traits::eof()) returnstrue, otherwise the sequence consisting of c[.](#3.sentence-2)
+
+[4](#4)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L4047)
+
+*Preconditions*: Every overriding definition of this virtual function
+obeys the following constraints:
+
+- [(4.1)](#4.1)
+
+  The effect of consuming a character on the associated output sequence is
+specified[.](#4.1.sentence-1)[270](#footnote-270 "That is, for each class derived from a specialization of basic_streambuf in this Clause ([stringbuf], [filebuf]), a specification of how consuming a character effects the associated output sequence is given. There is no requirement on a program-defined class.")
+
+- [(4.2)](#4.2)
+
+  Letr be the number of characters in the pending sequence not consumed[.](#4.2.sentence-1)
+  Ifr is nonzero thenpbase() andpptr() are set so that:pptr() - pbase() == r and the r characters starting atpbase() are the associated output stream[.](#4.2.sentence-2)
+  In case r is zero (all characters of the pending sequence have been consumed)
+then eitherpbase() is set tonullptr,
+orpbase() andpptr() are both set to the same non-null value[.](#4.2.sentence-3)
+
+- [(4.3)](#4.3)
+
+  The function may fail if either
+appending some character to the associated output stream fails or
+if it is unable to establishpbase() andpptr() according to the above rules[.](#4.3.sentence-1)
+
+[5](#5)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L4097)
+
+*Returns*: traits::eof() or throws an exception
+if the function fails[.](#5.sentence-1)
+
+Otherwise,
+returns some value other thantraits::eof() to indicate success[.](#5.sentence-2)[271](#footnote-271 "Typically, overflow returns c to indicate success, except when traits::eq_int_type(c, traits::eof()) returns true, in which case it returns traits::not_eof(c).")
+
+[6](#6)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L4118)
+
+*Default behavior*: Returnstraits::eof()[.](#6.sentence-1)
+
+[7](#7)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L4123)
+
+*Remarks*: The member functionssputc() andsputn() call this function in case that
+no room can be found in the put buffer enough to accommodate the
+argument character sequence[.](#7.sentence-1)
+
+[270)](#footnote-270)[270)](#footnoteref-270)
+
+That is, for each class derived from a specialization ofbasic_streambuf in this Clause ([[stringbuf]](stringbuf "31.8.2 Class template basic_stringbuf"), [[filebuf]](filebuf "31.10.3 Class template basic_filebuf")),
+a specification of how consuming a character effects the associated output sequence is given[.](#footnote-270.sentence-1)
+
+There is no requirement on a program-defined class[.](#footnote-270.sentence-2)
+
+[271)](#footnote-271)[271)](#footnoteref-271)
+
+Typically,overflow returns c to indicate success, except whentraits::eq_int_type(c, traits::eof()) returnstrue,
+in which case it returnstraits::not_eof(c)[.](#footnote-271.sentence-1)
--- a/cppdraft/streambuf/virtuals.md
+++ b/cppdraft/streambuf/virtuals.md
@@ -0,0 +1,502 @@
+[streambuf.virtuals]
+
+# 31 Input/output library [[input.output]](./#input.output)
+
+## 31.6 Stream buffers [[stream.buffers]](stream.buffers#streambuf.virtuals)
+
+### 31.6.3 Class template basic_streambuf [[streambuf]](streambuf#virtuals)
+
+#### 31.6.3.5 Virtual functions [streambuf.virtuals]
+
+#### [31.6.3.5.1](#streambuf.virt.locales) Locales [[streambuf.virt.locales]](streambuf.virt.locales)
+
+[ð](#lib:imbue,basic_streambuf)
+
+`void imbue(const locale&);
+`
+
+[1](#streambuf.virt.locales-1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3594)
+
+*Effects*: Change any translations based on locale[.](#streambuf.virt.locales-1.sentence-1)
+
+[2](#streambuf.virt.locales-2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3598)
+
+*Remarks*: Allows the derived class to be informed of changes in locale at the
+time they occur[.](#streambuf.virt.locales-2.sentence-1)
+
+Between invocations of this function a class derived
+from streambuf can safely cache results of calls to locale functions
+and to members of facets so obtained[.](#streambuf.virt.locales-2.sentence-2)
+
+[3](#streambuf.virt.locales-3)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3606)
+
+*Default behavior*: Does nothing[.](#streambuf.virt.locales-3.sentence-1)
+
+#### [31.6.3.5.2](#streambuf.virt.buffer) Buffer management and positioning [[streambuf.virt.buffer]](streambuf.virt.buffer)
+
+[ð](#lib:setbuf,basic_streambuf)
+
+`basic_streambuf* setbuf(char_type* s, streamsize n);
+`
+
+[1](#streambuf.virt.buffer-1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3619)
+
+*Effects*: Influences stream buffering in a way that is defined separately for each class
+derived frombasic_streambuf in this Clause ([[stringbuf.virtuals]](stringbuf.virtuals "31.8.2.5 Overridden virtual functions"), [[filebuf.virtuals]](filebuf.virtuals "31.10.3.5 Overridden virtual functions"))[.](#streambuf.virt.buffer-1.sentence-1)
+
+[2](#streambuf.virt.buffer-2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3626)
+
+*Default behavior*: Does nothing[.](#streambuf.virt.buffer-2.sentence-1)
+
+Returnsthis[.](#streambuf.virt.buffer-2.sentence-2)
+
+[ð](#lib:seekoff,basic_streambuf)
+
+`pos_type seekoff(off_type off, ios_base::seekdir way,
+                 ios_base::openmode which
+                   = ios_base::in | ios_base::out);
+`
+
+[3](#streambuf.virt.buffer-3)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3641)
+
+*Effects*: Alters the stream positions within one or more of
+the controlled sequences in a way that is defined separately for each class
+derived frombasic_streambuf in this Clause ([[stringbuf.virtuals]](stringbuf.virtuals "31.8.2.5 Overridden virtual functions"), [[filebuf.virtuals]](filebuf.virtuals "31.10.3.5 Overridden virtual functions"))[.](#streambuf.virt.buffer-3.sentence-1)
+
+[4](#streambuf.virt.buffer-4)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3649)
+
+*Default behavior*: Returnspos_type(off_type(-1))[.](#streambuf.virt.buffer-4.sentence-1)
+
+[ð](#lib:seekpos,basic_streambuf)
+
+`pos_type seekpos(pos_type sp,
+                 ios_base::openmode which
+                   = ios_base::in | ios_base::out);
+`
+
+[5](#streambuf.virt.buffer-5)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3663)
+
+*Effects*: Alters the stream positions within one or more of
+the controlled sequences in a way that is defined separately for each class
+derived frombasic_streambuf in this Clause ([[stringbuf]](stringbuf "31.8.2 Class template basic_stringbuf"), [[filebuf]](filebuf "31.10.3 Class template basic_filebuf"))[.](#streambuf.virt.buffer-5.sentence-1)
+
+[6](#streambuf.virt.buffer-6)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3671)
+
+*Default behavior*: Returnspos_type(off_type(-1))[.](#streambuf.virt.buffer-6.sentence-1)
+
+[ð](#lib:sync,basic_streambuf)
+
+`int sync();
+`
+
+[7](#streambuf.virt.buffer-7)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3683)
+
+*Effects*: Synchronizes the controlled sequences with the arrays[.](#streambuf.virt.buffer-7.sentence-1)
+
+That is, ifpbase() is non-null the characters betweenpbase() andpptr() are written to the controlled sequence[.](#streambuf.virt.buffer-7.sentence-2)
+
+The pointers may then be reset as appropriate[.](#streambuf.virt.buffer-7.sentence-3)
+
+[8](#streambuf.virt.buffer-8)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3695)
+
+*Returns*: -1 on failure[.](#streambuf.virt.buffer-8.sentence-1)
+
+What constitutes failure is determined by each derived class ([[filebuf.virtuals]](filebuf.virtuals "31.10.3.5 Overridden virtual functions"))[.](#streambuf.virt.buffer-8.sentence-2)
+
+[9](#streambuf.virt.buffer-9)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3700)
+
+*Default behavior*: Returns zero[.](#streambuf.virt.buffer-9.sentence-1)
+
+#### [31.6.3.5.3](#streambuf.virt.get) Get area [[streambuf.virt.get]](streambuf.virt.get)
+
+[ð](#lib:showmanyc,basic_streambuf)
+
+`streamsize showmanyc();[267](#footnote-267 "The morphemes of showmanyc are âes-how-many-seeâ, not âshow-manicâ.")
+`
+
+[1](#streambuf.virt.get-1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3716)
+
+*Returns*: An estimate of the number of
+characters available in the sequence, or â1[.](#streambuf.virt.get-1.sentence-1)
+
+If it returns
+a positive value, then successive calls tounderflow() will not returntraits::eof() until at least that number of characters have been
+extracted from the stream[.](#streambuf.virt.get-1.sentence-2)
+
+Ifshowmanyc() returns â1, then calls tounderflow() oruflow() will fail[.](#streambuf.virt.get-1.sentence-3)[268](#footnote-268 "underflow or uflow can fail by throwing an exception prematurely. The intention is not only that the calls will not return eof() but that they will return âimmediatelyâ.")
+
+[2](#streambuf.virt.get-2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3744)
+
+*Default behavior*: Returns zero[.](#streambuf.virt.get-2.sentence-1)
+
+[3](#streambuf.virt.get-3)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3748)
+
+*Remarks*: Usestraits::eof()[.](#streambuf.virt.get-3.sentence-1)
+
+[ð](#lib:xsgetn,basic_streambuf)
+
+`streamsize xsgetn(char_type* s, streamsize n);
+`
+
+[4](#streambuf.virt.get-4)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3760)
+
+*Effects*: Assigns up to n characters to successive elements of
+the array whose first element is designated by s[.](#streambuf.virt.get-4.sentence-1)
+
+The characters assigned are read from the input sequence as if
+by repeated calls tosbumpc()[.](#streambuf.virt.get-4.sentence-2)
+
+Assigning stops when either n characters
+have been assigned or a call tosbumpc() would returntraits::eof()[.](#streambuf.virt.get-4.sentence-3)
+
+[5](#streambuf.virt.get-5)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3773)
+
+*Returns*: The number of characters assigned[.](#streambuf.virt.get-5.sentence-1)[269](#footnote-269 "Classes derived from basic_streambuf can provide more efficient ways to implement xsgetn() and xsputn() by overriding these definitions from the base class.")
+
+[6](#streambuf.virt.get-6)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3786)
+
+*Remarks*: Usestraits::eof()[.](#streambuf.virt.get-6.sentence-1)
+
+[ð](#lib:underflow,basic_streambuf)
+
+`int_type underflow();
+`
+
+[7](#streambuf.virt.get-7)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3798)
+
+The[*pending sequence*](#def:pending_sequence) of characters is defined as the concatenation of
+
+- [(7.1)](#streambuf.virt.get-7.1)
+
+the empty sequence if gptr() is null, otherwise the
+characters in
+[gptr(), egptr()),
+followed by
+
+- [(7.2)](#streambuf.virt.get-7.2)
+
+some (possibly empty) sequence of characters read from the input sequence[.](#streambuf.virt.get-7.sentence-1)
+
+[8](#streambuf.virt.get-8)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3811)
+
+The[*result character*](#def:result_character) is
+the first character of the pending sequence if it is non-empty,
+otherwise
+the next character that would be read from the input sequence[.](#streambuf.virt.get-8.sentence-1)
+
+[9](#streambuf.virt.get-9)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3819)
+
+The[*backup sequence*](#def:backup_sequence) is the empty sequence if eback() is null, otherwise the
+characters in
+[eback(), gptr())[.](#streambuf.virt.get-9.sentence-1)
+
+[10](#streambuf.virt.get-10)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3826)
+
+*Effects*: The function sets up thegptr() andegptr() such that
+if the pending sequence is non-empty, thenegptr() is non-null and
+the characters in [gptr(), egptr()) are
+the characters in the pending sequence,
+otherwise
+either gptr() is null orgptr() == egptr()[.](#streambuf.virt.get-10.sentence-1)
+
+[11](#streambuf.virt.get-11)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3843)
+
+Ifeback() andgptr() are non-null then the function is not constrained as to their contents, but the âusual backup conditionâ is that either
+
+- [(11.1)](#streambuf.virt.get-11.1)
+
+the backup sequence contains at leastgptr() - eback() characters, in which case the characters in
+[eback(), gptr())
+agree with the lastgptr() - eback() characters of the backup sequence, or
+
+- [(11.2)](#streambuf.virt.get-11.2)
+
+the characters in [gptr() - n, gptr())
+agree with the backup sequence (where n is the length of the backup sequence)[.](#streambuf.virt.get-11.sentence-1)
+
+[12](#streambuf.virt.get-12)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3863)
+
+*Returns*: traits::to_int_type(c),
+where c is the first*character* of the[*pending sequence*](#def:pending_sequence),
+without moving the input sequence position past it[.](#streambuf.virt.get-12.sentence-1)
+
+If the pending sequence is null then the function returnstraits::eof() to indicate failure[.](#streambuf.virt.get-12.sentence-2)
+
+[13](#streambuf.virt.get-13)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3875)
+
+*Default behavior*: Returnstraits::eof()[.](#streambuf.virt.get-13.sentence-1)
+
+[14](#streambuf.virt.get-14)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3880)
+
+*Remarks*: The public members ofbasic_streambuf call this virtual function only ifgptr() is null orgptr() >= egptr()[.](#streambuf.virt.get-14.sentence-1)
+
+[ð](#lib:uflow,basic_streambuf)
+
+`int_type uflow();
+`
+
+[15](#streambuf.virt.get-15)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3896)
+
+*Preconditions*: The constraints are the same as forunderflow(),
+except that the result character is transferred from the pending
+sequence to the backup sequence, and the pending sequence is not empty before the transfer[.](#streambuf.virt.get-15.sentence-1)
+
+[16](#streambuf.virt.get-16)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3903)
+
+*Default behavior*: Callsunderflow()[.](#streambuf.virt.get-16.sentence-1)
+
+Ifunderflow() returnstraits::eof(),
+returnstraits::eof()[.](#streambuf.virt.get-16.sentence-2)
+
+Otherwise, returns the value oftraits::to_int_type(*gptr()) and increments the value of the next pointer for the input sequence[.](#streambuf.virt.get-16.sentence-3)
+
+[17](#streambuf.virt.get-17)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3917)
+
+*Returns*: traits::eof() to indicate failure[.](#streambuf.virt.get-17.sentence-1)
+
+[267)](#footnote-267)[267)](#footnoteref-267)
+
+The morphemes of showmanyc are âes-how-many-seeâ, not âshow-manicâ[.](#footnote-267.sentence-1)
+
+[268)](#footnote-268)[268)](#footnoteref-268)
+
+underflow oruflow can fail by throwing an exception prematurely[.](#footnote-268.sentence-1)
+
+The intention is not only that the calls will not returneof() but that they will return âimmediatelyâ[.](#footnote-268.sentence-2)
+
+[269)](#footnote-269)[269)](#footnoteref-269)
+
+Classes derived frombasic_streambuf can provide more efficient ways to implementxsgetn() andxsputn() by overriding these definitions from the base class[.](#footnote-269.sentence-1)
+
+#### [31.6.3.5.4](#streambuf.virt.pback) Putback [[streambuf.virt.pback]](streambuf.virt.pback)
+
+[ð](#lib:pbackfail,basic_streambuf)
+
+`int_type pbackfail(int_type c = traits::eof());
+`
+
+[1](#streambuf.virt.pback-1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3931)
+
+The[*pending sequence*](#def:pending_sequence) is defined as forunderflow(),
+with the modifications that
+
+- [(1.1)](#streambuf.virt.pback-1.1)
+
+  Iftraits::eq_int_type(c, traits::eof()) returnstrue,
+then the input sequence is backed up one character before the pending sequence is determined[.](#streambuf.virt.pback-1.1.sentence-1)
+
+- [(1.2)](#streambuf.virt.pback-1.2)
+
+  Iftraits::eq_int_type(c, traits::eof()) returns false, then c is prepended[.](#streambuf.virt.pback-1.2.sentence-1)
+  Whether the input sequence is backed up or modified in any other way is unspecified[.](#streambuf.virt.pback-1.2.sentence-2)
+
+[2](#streambuf.virt.pback-2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3951)
+
+*Postconditions*: On return, the constraints ofgptr(),eback(),
+andpptr() are the same as forunderflow()[.](#streambuf.virt.pback-2.sentence-1)
+
+[3](#streambuf.virt.pback-3)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3961)
+
+*Returns*: traits::eof() to indicate failure[.](#streambuf.virt.pback-3.sentence-1)
+
+Failure may occur because the input sequence could not be backed up, or if for some
+other reason the pointers cannot be set consistent with the constraints[.](#streambuf.virt.pback-3.sentence-2)
+
+pbackfail() is called only when put back has really failed[.](#streambuf.virt.pback-3.sentence-3)
+
+[4](#streambuf.virt.pback-4)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3970)
+
+Returns some value other thantraits::eof() to indicate success[.](#streambuf.virt.pback-4.sentence-1)
+
+[5](#streambuf.virt.pback-5)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3975)
+
+*Default behavior*: Returnstraits::eof()[.](#streambuf.virt.pback-5.sentence-1)
+
+[6](#streambuf.virt.pback-6)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L3980)
+
+*Remarks*: The public functions ofbasic_streambuf call this virtual function only whengptr() is null,gptr() == eback(),
+ortraits::eq(traits::to_char_type(c), gptr()[-1]) returnsfalse[.](#streambuf.virt.pback-6.sentence-1)
+
+Other calls shall also satisfy that constraint[.](#streambuf.virt.pback-6.sentence-2)
+
+#### [31.6.3.5.5](#streambuf.virt.put) Put area [[streambuf.virt.put]](streambuf.virt.put)
+
+[ð](#lib:xsputn,basic_streambuf)
+
+`streamsize xsputn(const char_type* s, streamsize n);
+`
+
+[1](#streambuf.virt.put-1)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L4003)
+
+*Effects*: Writes up to n characters to the output sequence as if
+by repeated calls tosputc(c)[.](#streambuf.virt.put-1.sentence-1)
+
+The characters written are obtained from successive elements of
+the array whose first element is designated by s[.](#streambuf.virt.put-1.sentence-2)
+
+Writing stops when either n characters have been written or
+a call tosputc(c) would returntraits::eof()[.](#streambuf.virt.put-1.sentence-3)
+
+It is unspecified whether the function calls overflow() when pptr() == epptr() becomes true or whether it achieves the same effects by other means[.](#streambuf.virt.put-1.sentence-4)
+
+[2](#streambuf.virt.put-2)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L4017)
+
+*Returns*: The number of characters written[.](#streambuf.virt.put-2.sentence-1)
+
+[ð](#lib:overflow,basic_streambuf)
+
+`int_type overflow(int_type c = traits::eof());
+`
+
+[3](#streambuf.virt.put-3)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L4028)
+
+*Effects*: Consumes some initial subsequence of the characters of the[*pending sequence*](#def:pending_sequence)[.](#streambuf.virt.put-3.sentence-1)
+
+The pending sequence is defined as the concatenation of
+
+- [(3.1)](#streambuf.virt.put-3.1)
+
+the empty sequence if pbase() is null, otherwise thepptr() - pbase() characters beginning atpbase(), followed by
+
+- [(3.2)](#streambuf.virt.put-3.2)
+
+the empty sequence
+iftraits::eq_int_type(c, traits::eof()) returnstrue, otherwise the sequence consisting of c[.](#streambuf.virt.put-3.sentence-2)
+
+[4](#streambuf.virt.put-4)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L4047)
+
+*Preconditions*: Every overriding definition of this virtual function
+obeys the following constraints:
+
+- [(4.1)](#streambuf.virt.put-4.1)
+
+  The effect of consuming a character on the associated output sequence is
+specified[.](#streambuf.virt.put-4.1.sentence-1)[270](#footnote-270 "That is, for each class derived from a specialization of basic_streambuf in this Clause ([stringbuf], [filebuf]), a specification of how consuming a character effects the associated output sequence is given. There is no requirement on a program-defined class.")
+
+- [(4.2)](#streambuf.virt.put-4.2)
+
+  Letr be the number of characters in the pending sequence not consumed[.](#streambuf.virt.put-4.2.sentence-1)
+  Ifr is nonzero thenpbase() andpptr() are set so that:pptr() - pbase() == r and the r characters starting atpbase() are the associated output stream[.](#streambuf.virt.put-4.2.sentence-2)
+  In case r is zero (all characters of the pending sequence have been consumed)
+then eitherpbase() is set tonullptr,
+orpbase() andpptr() are both set to the same non-null value[.](#streambuf.virt.put-4.2.sentence-3)
+
+- [(4.3)](#streambuf.virt.put-4.3)
+
+  The function may fail if either
+appending some character to the associated output stream fails or
+if it is unable to establishpbase() andpptr() according to the above rules[.](#streambuf.virt.put-4.3.sentence-1)
+
+[5](#streambuf.virt.put-5)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L4097)
+
+*Returns*: traits::eof() or throws an exception
+if the function fails[.](#streambuf.virt.put-5.sentence-1)
+
+Otherwise,
+returns some value other thantraits::eof() to indicate success[.](#streambuf.virt.put-5.sentence-2)[271](#footnote-271 "Typically, overflow returns c to indicate success, except when traits::eq_int_type(c, traits::eof()) returns true, in which case it returns traits::not_eof(c).")
+
+[6](#streambuf.virt.put-6)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L4118)
+
+*Default behavior*: Returnstraits::eof()[.](#streambuf.virt.put-6.sentence-1)
+
+[7](#streambuf.virt.put-7)
+
+[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/iostreams.tex#L4123)
+
+*Remarks*: The member functionssputc() andsputn() call this function in case that
+no room can be found in the put buffer enough to accommodate the
+argument character sequence[.](#streambuf.virt.put-7.sentence-1)
+
+[270)](#footnote-270)[270)](#footnoteref-270)
+
+That is, for each class derived from a specialization ofbasic_streambuf in this Clause ([[stringbuf]](stringbuf "31.8.2 Class template basic_stringbuf"), [[filebuf]](filebuf "31.10.3 Class template basic_filebuf")),
+a specification of how consuming a character effects the associated output sequence is given[.](#footnote-270.sentence-1)
+
+There is no requirement on a program-defined class[.](#footnote-270.sentence-2)
+
+[271)](#footnote-271)[271)](#footnoteref-271)
+
+Typically,overflow returns c to indicate success, except whentraits::eq_int_type(c, traits::eof()) returnstrue,
+in which case it returnstraits::not_eof(c)[.](#footnote-271.sentence-1)