Namespaces
Variants
Views
Actions

std::basic_istream::peek

From cppreference.com
< cpp‎ | io‎ | basic istream
Revision as of 06:31, 14 June 2013 by P12 (Talk | contribs)

int_type peek();

Behaves as UnformattedInputFunction. After constructing and testing the sentry object, reads the next character from the input stream without extracting it.

Contents

Parameters

(none)

Return value

If good() == true, returns the next character as obtained by rdbuf()->sgetc()

Otherwise, returns Traits::eof().

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

#include <sstream>
#include <iostream>
int main()
{
    std::istringstream s1("Hello, world.");
    char c1 = s1.peek();
    char c2 = s1.get();
    std::cout << "Peeked: " << c1 << " got: " << c2 << '\n';
}

Output:

Peeked: H got: H

See also

extracts characters
(public member function) [edit]
unextracts a character
(public member function) [edit]