structeq: new module.

[ccan] / ccan / structeq / _info

diff --git a/ccan/structeq/_info b/ccan/structeq/_info
new file mode 100644 (file)
index 0000000..d66e296
--- /dev/null
+++ b/ccan/structeq/_info
@@ -0,0 +1,57 @@
+#include "config.h"
+#include <stdio.h>
+#include <string.h>
+
+/**
+ * structeq - bitwise comparison of structs.
+ *
+ * This is a replacement for memcmp, which checks the argument types are the
+ * same.
+ *
+ * License: CC0 (Public domain)
+ * Author: Rusty Russell <rusty@rustcorp.com.au>
+ *
+ * Example:
+ *     #include <ccan/structeq/structeq.h>
+ *     #include <ccan/build_assert/build_assert.h>
+ *     #include <assert.h>
+ *     
+ *     struct mydata {
+ *             int start, end;
+ *     };
+ *     
+ *     int main(void)
+ *     {
+ *             struct mydata a, b;
+ *     
+ *             // No padding in struct, otherwise this doesn't work!
+ *             BUILD_ASSERT(sizeof(a) == sizeof(a.start) + sizeof(a.end));
+ *     
+ *             a.start = 100;
+ *             a.end = 101;
+ *     
+ *             b.start = 100;
+ *             b.end = 101;
+ *     
+ *             // They are equal.
+ *             assert(structeq(&a, &b));
+ *     
+ *             b.end++;
+ *             // Now they are not.
+ *             assert(!structeq(&a, &b));
+ *     
+ *             return 0;
+ *     }
+ */
+int main(int argc, char *argv[])
+{
+       /* Expect exactly one argument */
+       if (argc != 2)
+               return 1;
+
+       if (strcmp(argv[1], "depends") == 0) {
+               return 0;
+       }
+
+       return 1;
+}