https://issues.dlang.org/show_bug.cgi?id=19009

          Issue ID: 19009
           Summary: core.internal.hash.hashOf default hash (absent
                    `toHash`) should be `@nogc`
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: enhancement
          Priority: P1
         Component: druntime
          Assignee: nobody@puremagic.com
          Reporter: n8sh.secondary@hotmail.com

The default `hashOf` implementation used for types that do not have `toHash` uses `toUbyte` to get the byte representation which during CTFE requires allocation but during execution does not. The compiler currently takes CTFE-only code into account when inferring attributes but we can give it some help.

--