`sizeof ((struct X *)0)->field` — conformance in C1999 specifically?
Specifically in ISO C 1999, not in C++ nor in any newer revision of C1, is it strictly conforming to use sizeof ((struct T *) 0)->field to determine the size of a struct field? For example
Is recursively calling main from its own parameters (abusing sizeof with VLAs) standard C99?
Disclaimer: my question isn’t practical at all, it’s more a question about 2 codes which allegedly abuse the rules and somewhat compile (with more or less warnings / errors according to the compiler).