issue 15371 - some traits should bypass the protection

[ghost]

The argumentation is in the bug tracker issue, but in short:

"__traits(getMember,...)" should always work, whatever is the member protection (as long as the symbol is a valid one).

The current limitation is problematic because it prevents to write functions related to traits in a separate dedicated modules (e.g mylib.traits)

See also this issue, it demonstrates why it could be interesting to give super-powers to traits: because the current limitation already affects phobos.

[adamdruppe]

This could fix my mistake with getProtection too which requires a symbol... which you can't get on private members right now.

[AndrejMitrovic]

This seems like something that requires approval. Also, would this allow someone to call a private function from another module?

Ping @WalterBright @andralex for thoughts.

[ghost]

Yes this would allow things that are completly illegal, but this is the point. The idea is to allow this with a kind of caution, e.g use this only if you know what you do because it can break the protection.

I'm curious to know if there could be another way to solve the problem exposed in the bugzilla issue (other than mixing a template to get the scope).

[WalterBright]

Maybe it would make sense to bypass the protection if one is not in @safe code.

[aubade]

Isn't @safe supposed to be about one specific thing (memory corruption)? Expanding it to mean "potentially poor programming practices" seems a very hazard-laden road to take

[dnadlinger]

Isn't @safe supposed to be about one specific thing (memory corruption)? Expanding it to mean "potentially poor programming practices" seems a very hazard-laden road to take

The connection to @safe is that accessing private members might invalidate state that a certain type relies on to provide safety guarantees. For example, a member function might be @trusted on grounds that the class has previously made sure some private pointer members are in a certain well-defined state.

[ghost]

You can close this PR, bugzilla issue is closed because of #6078

[JinShil]

See also comments starting here: #7241 (comment)

[RazvanN7]

Closing this as 2 other PRs have been submitted for this:

#9325
#9585