diff options
Diffstat (limited to 'optional.h')
| -rw-r--r-- | optional.h | 56 |
1 files changed, 50 insertions, 6 deletions
@@ -9,21 +9,65 @@ #include <stdbool.h> +/** + * OPTIONAL - declare an object that optionally holds type @T + * @T: the type of data to hold. + * @name: the name of the variable or struct field. + */ #define OPTIONAL(T, name) struct { bool has; T data; } name +/** + * OPTNONE - initialize an OPTIONAL object to hold nothing. + */ #define OPTNONE { .has = false } + +/** + * OPTSOME - initialize an OPTIONAL object to hold something. + * @d: data to hold. + */ #define OPTSOME(d) { .has = true, .data = d } -#define optional_set_none(opt) opt.has = false +/** + * opt_set_none - set an OPTIONAL object to hold nothing. + * @opt: OPTIONAL object. + */ +#define opt_set_none(opt) opt.has = false -#define optional_set_some(opt, d) \ +/** + * opt_set_some - set an OPTIONAL object to hold something. + * @opt: OPTIONAL object. + * @d: data to hold. + */ +#define opt_set_some(opt, d) \ (opt.has = true, opt.data = d) -#define optional_has(opt) (opt.has) +/** + * opt_has - true if an OPTIONAL object has something. + * @opt: OPTIONAL object. + */ +#define opt_has(opt) (opt.has) + +/** + * opt_hasnt - true if an OPTIONAL object has nothing. + * @opt: OPTIONAL object. + */ +#define opt_hasnt(opt) (!opt.has) -#define optional_hasnt(opt) (!opt.has) +/** + * opt_unwrap - if there's something in @src, copy it to @dst. + * @src: OPTIONAL object to copy data of type T from. + * @dst: variable of type T to copy to. + * + * Returns true if there was something, false if there wasn't. + */ +#define opt_unwrap(src, dst) \ + (opt_has(src) ? (dst = src.data, true) : (false)) -#define optional_unwrap(src, dst) \ - (optional_has(src) ? (dst = src.data, true) : (false)) +/** + * opt_default - get something from @src or default to @def. + * @src: OPTIONAL object to get data from. + * @def: default value if there's nothing. + */ +#define opt_default(src, def) opt_has(src) ? src.data : def #endif |