std::basic_istream::ignore

From cppreference.com


basic_istream& ignore( std::streamsize count = 1, int_type delim = Traits::eof() );

Extracts and discards characters from the input stream until and including delim.

ignore behaves as an UnformattedInputFunction. After constructing and checking the sentry object, it extracts characters from the stream and discards them until any one of the following conditions occurs:

count characters were extracted. This test is disabled in the special case when count equals std::numeric_limits<std::streamsize>::max()

end of file conditions occurs in the input sequence, in which case the function calls setstate(eofbit)

the next available character c in the input sequence is delim, as determined by Traits::eq_int_type(Traits::to_int_type(c), delim). The delimiter character is extracted and discarded. This test is disabled if delim is Traits::eof()

#include <iostream>
#include <sstream>
#include <limits>
 
int main()
{
    std::istringstream input("1\n"
                             "some non-numeric input\n"
                             "2\n");
    for(;;) {
        int n;
        input >> n;
 
        if (input.eof() || input.bad()) {
            break;
        } else if (input.fail()) {
            input.clear(); // unset failbit
            input.ignore(std::numeric_limits<std::streamsize>::max(), '\n'); // skip bad input
        } else {
            std::cout << n << '\n';
        }
    }
}

Output:

1
2

[edit] See also


get	extracts characters (public member function)

getline	extracts characters until the given character is found (public member function)

Language
Standard library headers
Concepts
Utilities library
Strings library
Containers library
Algorithms library
Iterators library
Numerics library
Input/output library
Localizations library
Regular expressions library (C++11)
Atomic operations library (C++11)
Thread support library (C++11)

std::basic_istream::ignore

Contents

[edit] Parameters

[edit] Return value

[edit] Example

[edit] See also

count	-	number of characters to extract
delim	-	delimiting character to stop the extraction at. It is also extracted.