Thank you very much for your quick response! Am Do., 30. Apr. 2020 um 00:39 Uhr schrieb Paul Eggert <egg...@cs.ucla.edu>: > > On 4/29/20 12:29 PM, Marc Nieper-Wißkirchen wrote: > > It would be great if the flexmember exported another macro, say > > XFLEXSIZEOF, which returned SIZE_MAX in case of arithmetic overflow. > > Something like this? > > /* Like FLEXSIZEOF, except yield SIZE_MAX on arithmetic overflow, > and N might be evaluated more than once. */ > > #define XFLEXSIZEOF_XSIZE(type, member, n) \ > (((n) <= FLEXSIZEOF (type, member, n) \ > && FLEXSIZEOF (type, member, n) <= (size_t) -1) \ > ? (size_t) FLEXSIZEOF (type, member, n) : (size_t) -1) > > A couple of problems with this approach: > > * It evaluates N more than once.
Couldn't this be solved by calling a static function that would be subject to be inlined? > > * If the FLEXSIZEOF calls appears in a ptrdiff_t context it might not > return the right value. ptrdiff_t is also a popular way > to compute sizes. Maybe a warning in the comment above the macro's definition would be enough. > > But perhaps it's good enough. Why would you prefer the (longer) name XFLEXSIZEOF_XSIZE vs XFLEXSIZEOF?
