• via Digitalmars-d-bugs (25/25) Dec 15 2016 https://issues.dlang.org/show_bug.cgi?id=16973

via Digitalmars-d-bugs <digitalmars-d-bugs puremagic.com> writes:

https://issues.dlang.org/show_bug.cgi?id=16973

          Issue ID: 16973
           Summary: `hashOf` has error-prone signature as `(T, seed)` may
                    be confused with `(ptr, length)`
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: major
          Priority: P1
         Component: druntime
          Assignee: nobody puremagic.com
          Reporter: verylonglogin.reg gmail.com

In our root `object` module we have a function `hashOf` [1] which accept any
type as the first parameter and optional seed as the second parameter.

This function signature is error-prone because its signature allows this
incorrect usage:
---
hashOf(arr.ptr, arr.length); // hash of ptr with seed set to length
---

It's a major issue as (ptr, length) usage pattern is common in programming and
incorrect hash function behavior is hard to debug.


[1] http://dlang.org/phobos/object.html#.hashOf

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