Re: [PATCH] uchar.h: define char16_t and char32_t for old c++

[Joakim Sindholt <opensource@zhasha.com>]

On Sun, Jul 08, 2018 at 03:19:03PM +0200, Szabolcs Nagy wrote:
> including uchar.h in c++ code is only well defined in c++11 onwards
> where char16_t and char32_t type definitions must be hidden since they
> are keywords.  however some c++ code compiled for older c++ standard
> include uchar.h too and they need the typedefs, this fix makes such
> code work.
> ---
>  include/uchar.h | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/include/uchar.h b/include/uchar.h
> index 8dabf1ed..7e5c4d40 100644
> --- a/include/uchar.h
> +++ b/include/uchar.h
> @@ -3,7 +3,9 @@
>  
>  #ifdef __cplusplus
>  extern "C" {
> -#else
> +#endif
> +
> +#if __cplusplus < 201103L
>  typedef unsigned short char16_t;
>  typedef unsigned char32_t;
>  #endif
> -- 
> 2.16.3

Isn't this a bit ill advised? I just did a little test to see how GCC
mangles the names and it looks troublesome:
char16_t func(char32_t *s); becomes _Z4funcPDi when -std=c++11
and when we add
typedef unsigned short char16_t;
typedef unsigned char32_t;
and compile it with -std=c++03 it becomes _Z4funcPj

Did I do something egregiously wrong? Because this seems like a recipe
for ABI incompatibility.