/*
 * Copyright 2013 Andrew Ayer
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 * 
 * Except as contained in this notice, the name(s) of the above copyright
 * holders shall not be used in advertising or otherwise to promote the
 * sale, use or other dealings in this Software without prior written
 * authorization.
 */
#pragma once

#include <istream>

/*
 * Alternative to std::istream::ignore(), which doesn't suffer from the extra underflow gcc bug:
 *  http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42857
 * Returns the number of bytes ignored.  Use the return value in lieu of gcount().
 */
template<class CharT, class Traits> std::streamsize ignore (std::basic_istream<CharT, Traits>& in, std::streamsize n =1, typename std::basic_istream<CharT, Traits>::int_type delim =Traits::eof())
{
	typename std::basic_istream<CharT, Traits>::sentry	sntry(in, true);
	std::streamsize						c = 0;
	if (sntry) {
		while (c < n) {
			typename std::basic_istream<CharT, Traits>::int_type	ch;
			try {
				ch = in.rdbuf()->sbumpc();
			} catch (...) {
				if (in.exceptions() & std::ios_base::badbit) {
					try {
						in.setstate(std::ios_base::badbit);
					} catch (...) { }
					throw;
				} else {
					in.setstate(std::ios_base::badbit);
					break;
				}
			}
			if (Traits::eq_int_type(ch, Traits::eof())) {
				// EOF
				in.setstate(std::ios_base::eofbit);
				break;
			} else if (Traits::eq_int_type(ch, delim)) {
				// Hit delim character
				++c;
				break;
			}
			++c;
		}
	}
	return c;
}