Bug 18432 – alias x = x where x is an imported symbol should result in an error

import std.stdio : writeln; alias writeln = writeln; This code should result in an error. On the other hand: import std.stdio : writeln; alias writeln = std.stio.writeln; should compile (and it does momentarily)

Actually, import std.stdio : writeln; alias writeln = std.stdio.writeln; Does not compile successfully, it issues an error : "Undefined identifier std.stdio.writeln".

(In reply to RazvanN from comment #1) > Actually, > > import std.stdio : writeln; > alias writeln = std.stdio.writeln; > > Does not compile successfully, it issues an error : "Undefined identifier > std.stdio.writeln". This one works (or rather fails) as expected. Importing using selective imports does not pull in the fully qualified name to the namespace. I'm not 100% sure on the first one, as it seems like if it works, it's simply a no-op. Can you give a reason why having it succeed is bad?

*** Issue 18480 has been marked as a duplicate of this issue. ***

PR : https://github.com/dlang/dmd/pull/7930

(In reply to Steven Schveighoffer from comment #2) > I'm not 100% sure on the first one, as it seems like if it works, it's > simply a no-op. Can you give a reason why having it succeed is bad? It's not a no-op but actually created some weird alias behind the scenes, sth. like writeln (declared alias) -> writeln (alias from selective import) -> std.stdio.writeln (real symbol), not too sure. But with Raszvan's recent protection fix for selective imports this started to ran into an infinite loop.

Something that might be contributing to the problem is the compiler currently allows selectively importing private aliases: --- moduleA.d module moduleA; private int i; private alias I = i; static this() { i = 10; } --- main.d import std.stdio; import moduleA : I; void main() { writeln(I); } That compiles and prints "10". The statement `import moduleA : I;` should fail because `I` is private.

Reduced test case --- moduleA.d module moduleA; template TestTemplate() { } --- moduleB.d module moduleB; import moduleA : TestTemplate; alias TestTemplate = TestTemplate; --- main.d import moduleB; alias TestTemplate = moduleB.TestTemplate; void main() { } compile with: dmd main.d moduleA.d moduleB.d

Fixed. See: https://github.com/dlang/dmd/pull/7954