basic_ios Class

项目
07/29/2015

The template class describes the storage and member functions common to both input streams (of template class basic_istream) and output streams (of template class basic_ostream) that depend on the template parameters. (The class ios_base describes what is common and not dependent on template parameters.) An object of class basic_ios<class Elem, class Traits> helps control a stream with elements of type Elem, whose character traits are determined by the class Traits.

template <class Elem, class Traits> 
   class basic_ios : public ios_base

Parameters

Elem
A type.
Traits
A variable of type char_traits.

Remarks

An object of class basic_ios<class Elem, class Traits> stores:

A tie pointer to an object of type basic_istream<Elem, Traits>.
A stream buffer pointer to an object of type basic_streambuf<Elem, Traits >.
Formatting information.
Stream state information in a base object of type ios_base.
A fill character in an object of type char_type.

Constructors

basic_ios

Constructs the basic_ios class.

Typedefs

char_type	A synonym for the template parameter Elem.
int_type	A synonym for Traits::int_type.
off_type	A synonym for Traits::off_type.
pos_type	A synonym for Traits::pos_type.
traits_type	A synonym for the template parameter Traits.

Member Functions

bad	Indicates a loss of integrity of the stream buffer.
clear	Clears all error flags.
copyfmt	Copies flags from one stream to another.
eof	Indicates if the end of a stream has been reached.
exceptions	Indicates which exceptions will be thrown by the stream.
fail	Indicates failure to extract a valid field from a stream.
fill	Specifies or returns the character that will be used when the text is not as wide as the stream.
good	Indicates the stream is in good condition.
imbue	Changes the locale.
init	Called by basic_ios constructors.
move	Moves all values, except the pointer to the stream buffer, from the parameter to the current object.
narrow	Finds the equivalent char to a given char_type.
rdbuf	Routes stream to specified buffer.
rdstate	Reads the state of bits for flags.
set_rdbuf	Assigns a stream buffer to be the read buffer for this stream object.
setstate	Sets additional flags.
swap	Exchanges the values in this basic_ios object for those of another basic_ios object. The pointers to the stream buffers are not swapped.
tie	Ensures that one stream is processed before another stream.
widen	Finds the equivalent char_type to a given char.

Operators

explicit operator bool	Allows use of a basic_ios object as a bool. Automatic type conversion is disabled to prevent common, unintended side effects.
operator void *	Indicates if the stream is still good.
operator!	Indicates if the stream is not bad.

Requirements

Header: <ios>

Namespace: std

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