C++ Library - <ios>



The C++ standard libraries provide an extensive set of input/output capabilities which we will see in subsequent chapters. This chapter will discuss very basic and most common I/O operations required for C++ programming.

Input-Output base classes and types for the IOStream hierarchy of classes as shown below −


Class templates

S.N. Member types Definition
1 basic_ios Base class for streams (type-dependent components
2 fpos Stream position class template


S.N. Member types Definition
1 ios Base class for streams (type-dependent components)
2 ios_base Base class for streams
3 wios Base class for wide character streams

Other types

S.N. Member types Definition
1 io_errc Input/output error conditions
2 streamoff Stream offset type
3 streampos Stream position type
4 streamsize Stream size type
5 wstreampos Wide stream position type

Format flag manipulators (functions)

Independent flags (switch on) −

S.N. Member types Definition
1 boolalpha Alphanumerical bool values
2 showbase Show numerical base prefixes
3 showpoint Show decimal point
4 showpos Show positive signs
5 skipws Skip whitespaces
6 unitbuf Flush buffer after insertions
7 uppercase Generate upper-case letters

Independent flags (switch off) −

S.N. Member types Definition
1 noboolalpha No alphanumerical bool values
2 noshowbase Do not show numerical base prefixes
3 noshowpoint Do not show decimal point
4 noshowpos Do not show positive signs
5 noskipws Do not skip whitespaces
6 nounitbuf Do not force flushes after insertions
7 nouppercase Do not generate upper case letters

Numerical base format flags ("basefield" flags) −

S.N. Member types Definition
1 dec Use decimal base
2 hex Use hexadecimal base
3 oct Use octal base

Floating-point format flags ("floatfield" flags) −

S.N. Member types Definition
1 fixed Use fixed floating-point notation
2 scientific Use scientific floating-point notation

Adustment format flags ("adjustfield" flags) −

S.N. Member types Definition
1 internal Adjust field by inserting characters at an internal position
2 left Adjust output to the left
3 right Adjust output to the right