ConcatString.hxx

/*
 * Copyright (C) 2014-2017 Max Kellermann <max.kellermann@gmail.com>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the
 * distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
 * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef CONCAT_STRING_HXX
#define CONCAT_STRING_HXX

#include <algorithm>

#include <string.h>

template<typename... Args>
size_t
FillLengths(size_t *lengths, const char *a, Args&&... args)
{
	return FillLengths(lengths, a) + FillLengths(lengths + 1, args...);
}

template<>
size_t
FillLengths(size_t *lengths, const char *a)
{
	return *lengths = strlen(a);
}

template<typename... Args>
char *
StringCat(char *p, const size_t *lengths, const char *a, Args&&... args)
{
	return StringCat(StringCat(p, lengths, a),
			 lengths + 1, args...);
}

template<>
char *
StringCat(char *p, const size_t *lengths, const char *a)
{
	return std::copy_n(a, *lengths, p);
}

#endif