Thou shalt have no other gods before the ANSI C standard 1644

No standard header is "built into the language core". There *is* a standard header for specifying integer widths, actually two headers (one is in effect a superset of the other), and it's freely available for use with nonconforming implementations that for whatever reason don't already provide it.

We already had that discussion, and you're quite wrong (as well as short-sighted).

Wrong as can be.

Any competent C programmer who *requires* an integer type to hold more than 16 bits for some purpose is *already* using (unsigned) long int, if 32 bits is known to suffice, or some typedef that is suitably set as part of platform tailoring.

An buttumption that type int is at least 32 bits wide on all possible platforms, when the language standard clearly says otherwise, is simple incompetence: at best woeful ignorance, and at worst a willful denial of reality.

Wrong. Platforms where type int is made greater than 32 bits are virtually always those where it is *more* efficient to use the wider type.

It's actually the bulk of today's target environments, and standards are *extremely* important there, largely because apps need to be readily migrated to different processor choices.