Some types in D are considered core to the language, but are defined in the library. For example:
size_t
ptrdiff_t
string
Object
TypeInfo
One can redefine these symbols in a module, but the resulting confusion in the error messages is really hard to parse by the person reading the message.
For example, I stared at an error message for about 20 minutes thinking I had a broken compiler that looked like this:
cannot pass argument `(*aa.impl).keysz` of type `immutable(uint)` to parameter `size_t len`
Of course, a normal immutable uint can be converted to a normal size_t. But I had accidentally redefined size_t to an enum.
My suggestion is to prefix any symbols that shadow ones defined in object.d with the fully qualified name. This could be based on a chart of core symbols like string or size_t, or it could be all symbols.
So if an error message is referring to a locally-defined size_t, it could say instead:
cannot pass argument `(*aa.impl).keysz` of type `immutable(uint)` to parameter `local.mod.size_t len`
This at least gives a hint that the type is not the size_t you are expecting.
Comment #1 by robert.schadek — 2024-12-13T19:35:50Z