[Issue 12927] New: Can't get at compile-time the immutable field of a struct instance in a TypeTuple

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=12927

          Issue ID: 12927
           Summary: Can't get at compile-time the immutable field of a
                    struct instance in a TypeTuple
           Product: D
           Version: D2
          Hardware: x86
                OS: Windows
            Status: NEW
          Keywords: rejects-valid
          Severity: regression
          Priority: P1
         Component: DMD
          Assignee: nobody at puremagic.com
          Reporter: bearophile_hugs at eml.cc

I am not fully sure this code is valid, but this used to work until recently:


alias TypeTuple(T...) = T;
struct Foo {
    int a;
    immutable int b;
}
struct Bar {
    auto foos = TypeTuple!(Foo(10, 20), Foo(10, 20));
    void bar() {
        enum i = 1;
        enum r = foos[i].b;

    }
}
void main() {}


With dmd 2.066alpha it gives:

temp.d(10,18): Error: value of 'this' is not known at compile time

I use this idiom to have struct instances with some mutable fields and with
some "enum" fields.

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