Rationale:

Toronto: C99 does not have these unsigned versions because the signed version exist just to define the implementation-defined behavior of signed integer division. Unsigned integer division has no implementation-defined behavior and thus does not need this treatment.

Proposed resolution:

Add to 26.7 [lib.c.math] paragraph 8:

struct udiv_t div(unsigned, unsigned);
struct uldiv_t div(unsigned long, unsigned long);
struct ulldiv_t div(unsigned long long, unsigned long long);

There is no div() function for unsigned integer types.

There are several possible resolutions. The simplest one is noted below. Other possibilities include a templated solution.