Constructor taking 64-bit integer missing on (some) Windows C++ compilers

Marc Glisse marc.glisse at
Mon Jun 8 21:30:49 UTC 2020

On Mon, 8 Jun 2020, Vincent Lefevre wrote:

> Couldn't the C interface *optionally* support more than C89?

I think the policy has been to have one uniform interface, and requiring 
C99 for GMP is likely to happen. I am generally in favor of optional 
support for __int128, which wouldn't be available everywhere, but more 
people need convincing ;-)

> But isn't the support for 128-bit integers incomplete (i.e. not all
> operations required by ISO C for an integer type are implemented)?

I believe there is a chicken and egg problem. If they implement 
everything, they have to bump intmax_t.

> Anyway you don't introduce a new large builtin integer type everyday.
> ABI breakages are annoying, but when they are rare, this could be
> acceptable. Moreover, I suspect that very few libraries/applications
> would be affected by a change of (u)intmax_t. And these are those
> that would benefit from such a change.

We don't get to pick what intmax_t refers to. I am also in favor of 
breaking ABIs once in a while to fix some mistakes or modernize some 
things, but that's not how redhat (for instance) sees things.

Marc Glisse

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