30 Input/output library [input.output]

30.5 Iostreams base classes [iostreams.base]

30.5.5 Class template basic_­ios [ios]

30.5.5.2 basic_­ios constructors [basic.ios.cons]

explicit basic_ios(basic_streambuf<charT, traits>* sb);
Effects: Constructs an object of class basic_­ios, assigning initial values to its member objects by calling init(sb).
basic_ios();
Effects: Constructs an object of class basic_­ios ([ios.base.cons]) leaving its member objects uninitialized.
The object shall be initialized by calling basic_­ios​::​init before its first use or before it is destroyed, whichever comes first; otherwise the behavior is undefined.
~basic_ios();
Remarks: The destructor does not destroy rdbuf().
void init(basic_streambuf<charT, traits>* sb);
Postconditions: The postconditions of this function are indicated in Table 105.
Table 105basic_­ios​::​init() effects
Element
Value
rdbuf()
sb
tie()
0
rdstate()
goodbit if sb is not a null pointer, otherwise badbit.
exceptions()
goodbit
flags()
skipws | dec
width()
0
precision()
6
fill()
widen(' ')
getloc()
a copy of the value returned by locale()
iarray
a null pointer
parray
a null pointer