Understanding common std.Io.Reader/Writer mistakes (0.15.1)

[npc1054657282]

`@fieldParentPtr()` is innocent; what is dangerous is modifying a local copy of a structure

I must apologize for my assertion, as I’ve found that const isn’t always reliable. A value that might be modified by an API could very well be const. A typical example I’ve found so far is ArenaAllocator . Not all of its members are pointers—its state member contains an end_index , which is actually modified by the API ArenaAllocator.allocator().alloc. However, because this modification is hidden by anyopaque , this value, while actually mutable, can be defined as const by the user without rece…

I’m very sorry. After reflection, I confirmed that my assertion that “copying const can guarantee correctness” was wrong.