diff options
| -rw-r--r-- | src/mpfr-impl.h | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/src/mpfr-impl.h b/src/mpfr-impl.h index 4465b96eb..cb7c752a5 100644 --- a/src/mpfr-impl.h +++ b/src/mpfr-impl.h @@ -2526,9 +2526,11 @@ extern "C" { which is assumed to be present (with a value in it) when the usual exponent field has the value MPFR_EXP_UBF. The goal of this compatible representation is to easily be able to support UBF in "normal" code - and hopefully avoid aliasing issues at the same time. And code that - accepts UBF in input should also accept mpfr_t as a consequence; this - makes mpfr_t to UBF conversion unnecessary. + using the public API. This is some form of "subtyping". + + Unfortunately this breaks aliasing rules, and C does not provide any way + to avoid that (except with additional syntax ugliness and API breakage): + https://news.ycombinator.com/item?id=11753236 The alignment requirement for __mpfr_ubf_struct (UBF) needs to be at least as strong as the one for __mpfr_struct (MPFR number); this is not required |