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+#include <string.h>
+#include "config.h"
+
+/**
+ * cast - routines for safer casting.
+ *
+ * Often you want to cast in a limited way, such as removing a const or
+ * switching between integer types. However, normal casts will work on
+ * almost any type, making them dangerous when the code changes.
+ *
+ * These C++-inspired macros serve two purposes: they make it clear the
+ * exact reason for the cast, and they also (with some compilers) cause
+ * errors when misused.
+ *
+ * Based on Jan Engelhardt's libHX macros: http://libhx.sourceforge.net/
+ *
+ * Author: Jan Engelhardt
+ * Maintainer: Rusty Russell <rusty@rustcorp.com.au>
+ * License: LGPL
+ *
+ * Example:
+ * // Given "test" contains "3 t's in 'test string'
+ * #include <ccan/cast/cast.h>
+ * #include <stdint.h>
+ * #include <stdio.h>
+ *
+ * // Find char @orig in @str, if @repl, replace them. Return number.
+ * static size_t find_chars(char *str, char orig, char repl)
+ * {
+ * size_t i, count = 0;
+ * for (i = 0; str[i]; i++) {
+ * if (str[i] == orig) {
+ * count++;
+ * if (repl)
+ * str[i] = repl;
+ * }
+ * }
+ * return count;
+ * }
+ *
+ * // Terrible hash function.
+ * static uint64_t hash_string(const unsigned char *str)
+ * {
+ * size_t i;
+ * uint64_t hash = 0;
+ * for (i = 0; str[i]; i++)
+ * hash += str[i];
+ * return hash;
+ * }
+ *
+ * int main(int argc, char *argv[])
+ * {
+ * uint64_t hash;
+ *
+ * // find_chars wants a non-const string, but doesn't
+ * // need it if repl == 0.
+ * printf("%zu %c's in 'test string'\n",
+ * find_chars(cast_const(char *, "test string"),
+ * argv[1][0], 0),
+ * argv[1][0]);
+ *
+ * // hash_string wants an unsigned char.
+ * hash = hash_string(cast_signed(unsigned char *, argv[1]));
+ *
+ * // Need a long long to hand to printf.
+ * printf("Hash of '%s' = %llu\n", argv[1],
+ * cast_static(unsigned long long, hash));
+ * return 0;
+ * }
+ *
+ */
+int main(int argc, char *argv[])
+{
+ /* Expect exactly one argument */
+ if (argc != 2)
+ return 1;
+
+ if (strcmp(argv[1], "depends") == 0) {
+ printf("ccan/build_assert\n");
+ return 0;
+ }
+
+ return 1;
+}