std::basic_istream<CharT,Traits>::peek - cppreference.com

From cppreference.com

int_typepeek();Behaves as

UnformattedInputFunction

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

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

Run this code

#include<iostream>#include<sstream>intmain(){std::istringstreams1("Hello, world.");charc1=s1.peek();charc2=s1.get();std::cout<<"Peeked: "<<c1<<" got: "<<c2<<'\n';}Output:

Peeked: H got: H See also

reads one character from the input sequence without advancing the sequence
(public member function of std::basic_streambuf<CharT,Traits>)

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extracts characters
(public member function)

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unextracts a character
(public member function)

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