+#ifndef CCAN_STRMAP_H
+#define CCAN_STRMAP_H
+#include "config.h"
+#include <ccan/tcon/tcon.h>
+#include <ccan/typesafe_cb/typesafe_cb.h>
+#include <stdlib.h>
+#include <stdbool.h>
+
+/**
+ * struct strmap - representation of a string map
+ *
+ * It's exposed here to allow you to embed it and so we can inline the
+ * trivial functions.
+ */
+struct strmap {
+ union {
+ struct node *n;
+ const char *s;
+ } u;
+ void *v;
+};
+
+/**
+ * STRMAP_MEMBERS - declare members for a type-specific strmap.
+ * @type: type for this map's values, or void * for any pointer.
+ *
+ * You use this to create your own typed strmap for a particular type.
+ * You can use an integer type, *but* remember you can't use "0" as a
+ * value!
+ *
+ * Example:
+ * struct strmap_intp {
+ * STRMAP_MEMBERS(int *);
+ * };
+ */
+#define STRMAP_MEMBERS(type) \
+ struct strmap raw; \
+ TCON(type canary)
+
+
+/**
+ * strmap_init - initialize a string map (empty)
+ * @map: the typed strmap to initialize.
+ *
+ * For completeness; if you've arranged for it to be NULL already you don't
+ * need this.
+ *
+ * Example:
+ * struct strmap_intp map;
+ *
+ * strmap_init(&map);
+ */
+#define strmap_init(map) strmap_init_(&(map)->raw)
+
+static inline void strmap_init_(struct strmap *map)
+{
+ map->u.n = NULL;
+}
+
+/**
+ * strmap_empty - is this string map empty?
+ * @map: the typed strmap to check.
+ *
+ * Example:
+ * if (!strmap_empty(&map))
+ * abort();
+ */
+#define strmap_empty(map) strmap_empty_(&(map)->raw)
+
+static inline bool strmap_empty_(const struct strmap *map)
+{
+ return map->u.n == NULL;
+}
+
+/**
+ * strmap_get - get a value from a string map
+ * @map: the typed strmap to search.
+ * @member: the string to search for.
+ *
+ * Returns the value, or NULL if it isn't in the map.
+ *
+ * Example:
+ * int *val = strmap_get(&map, "hello");
+ * if (val)
+ * printf("hello => %i\n", *val);
+ */
+#define strmap_get(map, member) \
+ tcon_cast((map), canary, strmap_get_(&(map)->raw, (member)))
+void *strmap_get_(const struct strmap *map, const char *member);
+
+/**
+ * strmap_add - place a member in the string map.
+ * @map: the typed strmap to add to.
+ * @member: the string to place in the map.
+ * @v: the (non-NULL) value.
+ *
+ * This returns false if we run out of memory, or (more normally) if that
+ * string already appears in the map.
+ *
+ * Note that the pointer is placed in the map, the string is not copied. If
+ * you want a copy in the map, use strdup(). Similarly for the value.
+ *
+ * Example:
+ * val = malloc(sizeof *val);
+ * *val = 17;
+ * if (!strmap_add(&map, "goodbye", val))
+ * printf("goodbye was already in the map\n");
+ */
+#define strmap_add(map, member, value) \
+ strmap_add_(&tcon_check((map), canary, (value))->raw, \
+ (member), (void *)(value))
+
+bool strmap_add_(struct strmap *map, const char *member, const void *value);
+
+/**
+ * strmap_del - remove a member from the string map.
+ * @map: the typed strmap to delete from.
+ * @member: the string to remove from the map.
+ * @valuep: the value (if non-NULL)
+ *
+ * This returns the string which was passed to strmap_map(), or NULL.
+ * This means that if you allocated a string (eg. using strdup()), you
+ * can free it here. Similarly, the value is returned in @valuep if
+ * @valuep is not NULL.
+ *
+ * Example:
+ * if (!strmap_del(&map, "goodbye", NULL))
+ * printf("goodbye was not in the map?\n");
+ */
+#define strmap_del(map, member, valuep) \
+ strmap_del_(&tcon_check_ptr((map), canary, valuep)->raw, \
+ (member), (void **)valuep)
+char *strmap_del_(struct strmap *map, const char *member, void **valuep);
+
+/**
+ * strmap_clear - remove every member from the map.
+ * @map: the typed strmap to clear.
+ *
+ * The map will be empty after this.
+ *
+ * Example:
+ * strmap_clear(&map);
+ */
+#define strmap_clear(map) strmap_clear_(&(map)->raw)
+
+void strmap_clear_(struct strmap *map);
+
+/**
+ * strmap_iterate - ordered iteration over a map
+ * @map: the typed strmap to iterate through.
+ * @handle: the function to call.
+ * @arg: the argument for the function (types should match).
+ *
+ * @handle's prototype should be:
+ * bool @handle(const char *member, type value, typeof(arg) arg)
+ *
+ * If @handle returns true, the iteration will stop.
+ * You should not alter the map within the @handle function!
+ *
+ * Example:
+ * struct strmap_intp {
+ * STRMAP_MEMBERS(int *);
+ * };
+ * static bool dump_some(const char *member, int *value, int *num)
+ * {
+ * // Only dump out num nodes.
+ * if (*(num--) == 0)
+ * return true;
+ * printf("%s=>%i\n", member, *value);
+ * return false;
+ * }
+ *
+ * static void dump_map(const struct strmap_intp *map)
+ * {
+ * int max = 100;
+ * strmap_iterate(map, dump_some, &max);
+ * if (max < 0)
+ * printf("... (truncated to 100 entries)\n");
+ * }
+ */
+#define strmap_iterate(map, handle, arg) \
+ strmap_iterate_(&(map)->raw, \
+ typesafe_cb_cast(bool (*)(const char *, \
+ void *, void *), \
+ bool (*)(const char *, \
+ tcon_type((map), canary), \
+ __typeof__(arg)), (handle)), \
+ (arg))
+void strmap_iterate_(const struct strmap *map,
+ bool (*handle)(const char *, void *, void *), void *data);
+
+
+/**
+ * strmap_prefix - return a submap matching a prefix
+ * @map: the map.
+ * @prefix: the prefix.
+ *
+ * This returns a pointer into @map, so don't alter @map while using
+ * the return value. You can use strmap_iterate(), strmap_get() or
+ * strmap_empty() on the returned pointer.
+ *
+ * Example:
+ * static void dump_prefix(const struct strmap_intp *map,
+ * const char *prefix)
+ * {
+ * int max = 100;
+ * printf("Nodes with prefix %s:\n", prefix);
+ * strmap_iterate(strmap_prefix(map, prefix), dump_some, &max);
+ * if (max < 0)
+ * printf("... (truncated to 100 entries)\n");
+ * }
+ */
+#if HAVE_TYPEOF
+#define strmap_prefix(map, prefix) \
+ ((const __typeof__(map))strmap_prefix_(&(map)->raw, (prefix)))
+#else
+#define strmap_prefix(map, prefix) \
+ ((const void *)strmap_prefix_(&(map)->raw, (prefix)))
+#endif
+
+const struct strmap *strmap_prefix_(const struct strmap *map,
+ const char *prefix);
+
+#endif /* CCAN_STRMAP_H */