If badbit was set on the last call to exceptions, the function rethrows the caught exception. It throws an exception of member type failure if the resulting error state flag is not goodbit and member exceptions was set to throw for that state.Īny exception thrown by an internal operation is caught and handled by the function, setting badbit.
Please, enter your first name followed by your surname: John SmithĬoncurrent access to the same stream object may cause data races, except for the standard stream objects cin and wcin when these are synchronized with stdio (in this case, no data races are initiated, although no guarantees are given on the order in which extracted characters are attributed to threads).Įxception safety Basic guarantee: if an exception is thrown, the object is in a valid state. If the operation sets an internal state flag that was registered with member exceptions, the function throws an exception of member type failure. Multiple flags may be set by a single operation. When set, the integrity of the stream may have been affected. The construction of sentry failed (such as when the stream state was not good before the call).Įrror on stream (such as when this function catches an exception thrown by an internal operation). The function stopped extracting characters because the input sequence has no more characters available ( end-of-file reached). After constructing and checking the sentry object, it extracts characters from the stream and discards them until any one of the. I think I get the main idea of the function it does, but I've seen some examples of accepting only numeric input that uses this function, and I'm not sure why it works. ignore behaves as an UnformattedInputFunction. I've been reading about istream::ignore( ) here. Member type int_type is an integral type able to represent any valid character value or the special end-of-file value.Įrrors are signaled by modifying the internal state flags: basicistream & ignore (std:: streamsize count 1, inttype delim Traits:: eof ()) Extracts and discards characters from the input stream until and including delim. If this is the end-of-file value ( traits_type::eof()), no character will compare equal, and thus exactly n characters will be discarded (unless the function fails or the end-of-file is reached). If this is exactly numeric_limits::max(), there is no limit: As many characters are extracted as needed until delim (or the end-of-file) is found.ĭelim Delimiting character: The function stops extracting characters as soon as an extracted character compares equal to this (using traits_type::eq). Parameters n Maximum number of characters to extract (and ignore). Then (if good), it extracts characters from its associated stream buffer object as if calling its member functions sbumpc or sgetc, and finally destroys the sentry object before returning. Internally, the function accesses the input sequence by first constructing a sentry object (with noskipws set to true). If this is reached prematurely (before either extracting n characters or finding delim), the function sets the eofbit flag. The function also stops extracting characters if the end-of-file is reached.
Extracts characters from the input sequence and discards them, until either n characters have been extracted, or one compares equal to delim.
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