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ios_base::fmtflags

Constants to specify the appearance of output.

namespace std {
   class ios_base {
   public:
      typedef implementation-defined-bitmask-type fmtflags;
      static const fmtflags boolalpha;
      static const fmtflags dec;
      static const fmtflags fixed;
      static const fmtflags hex;
      static const fmtflags internal;
      static const fmtflags left;
      static const fmtflags oct;
      static const fmtflags right;
      static const fmtflags scientific;
      static const fmtflags showbase;
      static const fmtflags showpoint;
      static const fmtflags showpos;
      static const fmtflags skipws;
      static const fmtflags unitbuf;
      static const fmtflags uppercase;
      static const fmtflags adjustfield;
      static const fmtflags basefield;
      static const fmtflags floatfield;
      ...
   };
}

Remarks

Supports the manipulators in ios.

The type is a bitmask type that describes an object that can store format flags. The distinct flag values (elements) are:

  • dec, to insert or extract integer values in decimal format.

  • hex, to insert or extract integer values in hexadecimal format.

  • oct, to insert or extract integer values in octal format.

  • showbase, to insert a prefix that reveals the base of a generated integer field.

  • internal, to pad to a field width as needed by inserting fill characters at a point internal to a generated numeric field. (For information on setting the field width, see setw).

  • left, to pad to a field width as needed by inserting fill characters at the end of a generated field (left justification).

  • right, to pad to a field width as needed by inserting fill characters at the beginning of a generated field (right justification).

  • boolalpha, to insert or extract objects of type bool as names (such as true and false) rather than as numeric values.

  • fixed, to insert floating-point values in fixed-point format (with no exponent field).

  • scientific, to insert floating-point values in scientific format (with an exponent field).

  • showpoint, to insert a decimal point unconditionally in a generated floating-point field.

  • showpos, to insert a plus sign in a nonnegative generated numeric field.

  • skipws, to skip leading white space before certain extractions.

  • unitbuf, to flush output after each insertion.

  • uppercase, to insert uppercase equivalents of lowercase letters in certain insertions.

In addition, several useful values are:

  • adjustfield, a bitmask defined as internal | left | right

  • basefield, defined as dec | hex | oct

  • floatfield, defined as fixed | scientific

For examples of functions that modify these format flags, see <ios> Members (under Manipulators) and <iomanip> Members.

Requirements

Header: <ios>

Namespace: std

See Also

Reference

ios_base Class

iostream Programming

iostreams Conventions