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-rw-r--r--include/stddef.h72
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diff --git a/include/stddef.h b/include/stddef.h
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+/**
+ * slibc — Yet another C library
+ * Copyright © 2015 Mattias Andrée (maandree@member.fsf.org)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef _STDDEF_H
+#define _STDDEF_H
+
+
+
+/**
+ * `NULL` is a zero-values constant, conventionally
+ * a `void`-pointer (it is specified this way in
+ * POSIX, it does not really matter and ISO C does
+ * not specify it this way), use to indicate that
+ * a pointer does not point to anything.
+ */
+#define NULL ((void*)0)
+
+
+/**
+ * Get the offset of a member in a `struct`, in bytes.
+ *
+ * For example. Consider the structure
+ * ```
+ * struct example
+ * {
+ * char offset_is_0[16];
+ * char offset_is_16[16];
+ * }
+ * ```
+ * `offsetof(struct example, offset_is_0)` evaluates to
+ * 0 because it is at the top of the structure.
+ * `offsetof(struct example, offset_is_16)` evaluates to
+ * 16 because the member above it in the structure
+ * has offset 0 and size 16. 0 + 16 = 16.
+ *
+ * @param type:identifier The identifier for a structure.
+ * @param member:identifier The identifier for a member, direct or indirect,
+ * of the structure.
+ * @return :size_t The offset of the member.
+ */
+#define offsetof(type, member) \
+ ((size_t)((char*)&(((type*)NULL)->member) - (char*)NULL))
+
+
+
+#define __NEED_ptrdiff_t
+#define __NEED_wchar_t
+#define __NEED_size_t
+#if __STDC_VERSION__ >= 201112L
+# define __NEED_max_align_t
+#endif
+
+#include <bits/types.h>
+
+
+
+#endif
+