30 Input/output library [input.output]

30.5 Iostreams base classes [iostreams.base]

30.5.6 ios_­base manipulators [std.ios.manip]

30.5.6.4 floatfield manipulators [floatfield.manip]

ios_base& fixed(ios_base& str);
Effects: Calls str.setf(ios_­base​::​fixed, ios_­base​::​floatfield).
Returns: str.
ios_base& scientific(ios_base& str);
Effects: Calls str.setf(ios_­base​::​scientific, ios_­base​::​floatfield).
Returns: str.
ios_base& hexfloat(ios_base& str);
Effects: Calls str.setf(ios_­base​::​fixed | ios_­base​::​scientific, ios_­base​::​floatfield).
Returns: str.
[Note
:
The more obvious use of ios_­base​::​hex to specify hexadecimal floating-point format would change the meaning of existing well-defined programs.
C++ 2003 gives no meaning to the combination of fixed and scientific.
end note
]
ios_base& defaultfloat(ios_base& str);
Effects: Calls str.unsetf(ios_­base​::​floatfield).
Returns: str.