THE STANDARD C++ CLASS LIBRARY in .NET

Print QR-Code in .NET THE STANDARD C++ CLASS LIBRARY

#include <iostream> istream &getline(char *buf, streamsize num); istream &getline(char *buf, streamsize num, char delim);

The getline( ) function is a member of istream getline(char *buf, streamsize num) reads characters into the array pointed to by buf until either num 1 characters have been read, a newline character has been found, or the end of the file has been encountered The array pointed to by buf will be null terminated by getline( ) If the newline character is encountered in the input stream, it is extracted but is not put into buf This function returns a reference to the stream getline(char *buf, streamsize num, char delim) reads characters into the array pointed to by buf until either num 1 characters have been read, the character specified by delim has been found, or the end of the file has been encountered The array pointed

to by buf will be null terminated by getline( ) If the delimiter character is encountered in the input stream, it is extracted but is not put into buf This function returns a reference to the stream Related functions are get( ) and read( )

#include <iostream> bool good() const;

The good( ) function is a member of ios The good( ) function returns true if no I/O errors have occurred in the associated stream; otherwise, it returns false Related functions are bad( ), fail( ), eof( ), clear( ), and rdstate( )

#include <iostream> istream &ignore(streamsize num = 1, int delim = EOF);

The ignore( ) function is a member of istream You can use the ignore( ) member function to read and discard characters from the input stream It reads and discards characters until either num characters have been ignored (1 by default) or until the character specified by delim is encountered (EOF by default) If the delimiting character is encountered, it is removed from the input stream The function returns a reference to the stream Related functions are get( ) and getline( )

#include <fstream> void fstream::open(const char *filename, ios::openmode mode = ios::in | ios:: out); void ifstream::open(const char *filename, ios::openmode mode = ios::in); void ofstream::open(const char *filename, ios::openmode mode = ios:: out | ios::trunc);

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The open( ) function is a member of fstream, ifstream, and ofstream A file is associated with a stream by using the open( ) function Here, filename is the name of the file, which may include a path specifier The value of mode determines how the file is opened It must be one (or more) of these values: ios::app ios::ate ios::binary ios::in ios::out ios::trunc You can combine two or more of these values by ORing them together Including ios::app causes all output to that file to be appended to the end This value can only be used with files capable of output Including ios::ate causes a seek to the end of the file to occur when the file is opened Although ios::ate causes a seek to the end-of-file, I/O operations can still occur anywhere within the file The ios::binary value causes the file to be opened for binary I/O operations By default, files are opened in text mode The ios::in value specifies that the file is capable of input The ios::out value specifies that the file is capable of output However, creating an ifstream stream implies input, and creating an ofstream stream implies output, and opening a file using fstream implies both input and output The ios::trunc value causes the contents of a preexisting file by the same name to be destroyed, and the file is truncated to zero length In all cases, if open( ) fails, the stream will be false Therefore, before using a file, you should test to make sure that the open operation succeeded Related functions are close( ), fstream( ), ifstream( ), and ofstream( )