[spec] "arithmetic type", not defined in https://dlang.org/spec/traits.html

[dlangBugzillaToGithub]

hsteoh reported this on 2018-01-16T22:28:56Z

Transferred from https://issues.dlang.org/show_bug.cgi?id=18246

Description

On https://dlang.org/spec/traits.html, section 25.1, __traits(isArithmetic, T) is defined as returning true if T is an arithmetic type.  However, what exactly constitutes an arithmetic type is not stated.  Are pointers considered arithmetic types, since D does have pointer *arithmetic*?

It would be best if the spec explicitly listed exactly which types are considered "arithmetic types", or for that matter "unsigned types", etc., rather than leaving it up to interpretation.