On Fri, 29 Jun 2018 10:39:33 +0200 Hans Åberg <haber...@telia.com> wrote: > > On 29 Jun 2018, at 09:39, Andy Wingo <wi...@pobox.com> wrote: > > > > It would seem that the first four > > features of C99 are OK for all platforms that we target, with the > > following caveats: > > > > * We should avoid using C++ keywords (e.g. throw) in Guile API files. > > > > * We might want to avoid mixed decls and statements in inline functions > > in Guile API files. > > > > We should probably avoid stdbool.h and compound literals, for C++ > > reasons. > > You might make a separate C++ header: It turned out too complicated for Bison > to maintain the compile as C++ generated C parser. > > > In Guile 3.0 (master branch), the types "scm_t_uint8" and so on are now > > deprecated. My recommendation is that all users switch to use > > e.g. "uint8_t", "ptrdiff_t", etc from <stdint.h> instead of the > > scm_t_uint8, etc definitions that they are now using. The definitions > > are compatible on all systems, AFAIU, and on GNU, scm_t_uint8 has long > > been a simple typedef for uint8_t. > > For C++, these are only optional, cf. [1], as they require no padding. So an > alternative is to typedef the obligatory int_fast<2^k>_t types, perhaps > leaving the API unchanged. > > 1. https://en.cppreference.com/w/cpp/types/integer
The fixed size integer types are optional in C99/11 also, depending on whether the platform provides a fixed size integer of the type in question without padding and (for negative integers) a two's complement representation. If, say, uint8_t is available in stdint.h for C, it will be available for C++. §21.4.1/2 of C++17 makes this even more explicit: "The [cstdint] header defines all types and macros the same as the C standard library header <stdint.h>". I imagine guile will not run on any platform that does not support 8 and 32 bit fixed size integers.