std::basic_istream<CharT,Traits>::tellg

 

C++

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Input/output library

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basic_osyncstream (C++20)

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streamoff

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std::basic_istream

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cinwcin

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basic_istream::basic_istream

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basic_istream::operator= (C++11)

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basic_istream::tellg

basic_istream::seekg

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basic_istream::sync

basic_istream::swap (C++11)

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basic_istream::sentry

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operator>>(std::basic_istream)

 

pos_type tellg();

Returns input position indicator of the current associated streambuf object.

Behaves as UnformattedInputFunction, except that gcount() is not affected. After constructing and checking the sentry object, if fail() == true, returns pos_type(-1). Otherwise, returns rdbuf()->pubseekoff(0, std::ios_base::cur, std::ios_base::in).

Parameters

(none)

Return value

The current position of the get pointer on success, pos_type(-1) on failure

Exceptions

failure if an error occurred (the error state flag is not goodbit) and exceptions() is set to throw for that state.

If an internal operation throws an exception, it is caught and badbit is set. If exceptions() is set for badbit, the exception is rethrown.

Example

Run this code

#include <iostream>
#include <string>
#include <sstream>
 
int main()
{
    std::string str = "Hello, world";
    std::istringstream in(str);
    std::string word;
    in >> word;
    std::cout << "After reading the word \"" << word
              << "\" tellg() returns " << in.tellg() << '\n';
}

Output:

After reading the word "Hello," tellg() returns 6

See also

seekoff [virtual]	repositions the file position, using relative addressing (virtual protected member function of std::basic_filebuf<CharT,Traits>)
seekoff [virtual]	repositions the next pointer in the input sequence, output sequence, or both, using relative addressing (virtual protected member function of std::basic_stringbuf<CharT,Traits,Allocator>)
seekoff [virtual]	repositions the next pointer in the input sequence, output sequence, or both, using relative addressing (virtual protected member function of std::strstreambuf)
seekg	sets the input position indicator (public member function)
tellp	returns the output position indicator (public member function of std::basic_ostream<CharT,Traits>)
seekp	sets the output position indicator (public member function of std::basic_ostream<CharT,Traits>)