Bug 6588 – Struct d'tors + immutable elements doesn't work

struct Task(Args...) { Args _args; this(Args args) { _args = args; } ~this() {} // Bug goes away without this. } alias Task!(int function(immutable int), immutable(int)) F; Error: can only initialize const member __args_field_1 inside constructor Error: this is not mutable

This is built-in opAssign issue. When struct has only dtor, built-in opAssign is implemented automatically by compiler with memberwise assign. struct Task(Args...) { Args _args; this(Args args) { _args = args; } ~this() {} // Bug goes away without this. // Inserted automatically by compiler. // This code does not have file positions, so error message displays // no position. ref typeof(this) opAssign(typeof(this) rhs) { this._args = rhs.args; // immutable field assign outside constructor causes error return this; } }

Compiles on 2.059 Win32

(In reply to comment #1) Thanks I think in my case I can then implement opAssign to skip the assignment of immutable fields. Here is a real short test case without templates: struct Bug6588 { immutable int x; ~this() {} } Also this is related: struct Bug6588 { immutable int x; ref Bug6588 test() { return this; } // this is not mutable ref const(Bug6588) test() { return this; } // ok } The compiler has a hard time with partial const/immutable structures.

I cannot reproduce this bug. Closing as WORKSFORME