how to check regmap start address

Hi Let's see how it looks: https://github.com/u-boot/u-boot/blob/master/include/regmap.h I first time ever see such thing like this: struct regmap_range { ulong start; ulong size; }; struct regmap { enum regmap_endianness_t endianness; int range_count; struct regmap_range ranges[0]; }; How I can get access to variable ranges it if is 0 size? Who develops this one and who reviewed:) Anyway If I have pointer to regmap can I check what is start variable in some other way?