Bug 12761 – rvalue object with alias this to lvalue produces rvalue

Given an object with an alias this that references an lvalue: //---- struct S { static int i; alias i this; } //---- Then, take two functions that take by auto-ref and ref: //---- void foo(T)(auto ref T i) { pragma(msg, __traits(isRef, i)); } void bar(ref int i); //---- Finally, call them with an "RValue s". The alias this from S should create an lvalue int: //---- void main() { foo!int(S()); bar(S()); } //---- However, it is not the case: This produces: false Error: function main.bar (ref int i) is not callable using argument types (S) I think this should work.

This bug report is invalid. Alias this creates a subtyping relation between S and I and should behave as inheritance in the case of classes. Take this example which represents the same pattern but in the case of classes: class A {} class B : A {} void fun(ref A a) {} void main() { fun(new B()); } You will get the same error: issue.d(8): Error: function issue.fun(ref A a) is not callable using argument types (B) issue.d(8): cannot pass rvalue argument new B of type issue.B to parameter ref A a

This bug report is invalid. Alias this creates a subtyping relation between S and int and should behave as inheritance in the case of classes. Take this example which represents the same pattern but in the case of classes: class A {} class B : A {} void fun(ref A a) {} void main() { fun(new B()); } You will get the same error: issue.d(8): Error: function issue.fun(ref A a) is not callable using argument types (B) issue.d(8): cannot pass rvalue argument new B of type issue.B to parameter ref A a Closing as invalid.