order: Module for comparison callbacks

[ccan] / ccan / order / test / fancy_cmp.h

diff --git a/ccan/order/test/fancy_cmp.h b/ccan/order/test/fancy_cmp.h
new file mode 100644 (file)
index 0000000..b794037
--- /dev/null
+++ b/ccan/order/test/fancy_cmp.h
@@ -0,0 +1,47 @@
+#ifndef _FANCY_CMP_H
+#define _FANCY_CMP_H
+
+struct cmp_info {
+       unsigned xcode;
+       int offset;
+};
+
+struct item {
+       unsigned value;
+       char *str;
+};
+
+static inline int fancy_cmp(const struct item *a, const struct item *b,
+                           struct cmp_info *ctx)
+{
+       unsigned vala = a->value ^ ctx->xcode;
+       unsigned valb = b->value ^ ctx->xcode;
+       const char *stra, *strb;
+
+       if (vala < valb)
+               return -1;
+       else if (valb < vala)
+               return 1;
+
+       stra = a->str + ctx->offset;
+       strb = b->str + ctx->offset;
+
+       return strcmp(stra, strb);
+}
+
+static inline int fancy_cmp_noctx(const void *av, const void *bv)
+{
+       const struct item *a = (const struct item *)av;
+       const struct item *b = (const struct item *)bv;
+       struct cmp_info ctx_default = {
+               .xcode = 0x1234,
+               .offset = 3,
+       };
+       total_order(default_order, struct item, struct cmp_info *) = {
+               fancy_cmp, &ctx_default,
+       };
+
+       return default_order.cb(a, b, default_order.ctx);
+}
+
+#endif /* _FANCY_CMP_H */