https://issues.dlang.org/show_bug.cgi?id=24565

          Issue ID: 24565
           Summary: out contract variable is implicitly const
           Product: D
           Version: D2
          Hardware: x86_64
                OS: Linux
            Status: NEW
          Severity: minor
          Priority: P1
         Component: dlang.org
          Assignee: nobody@puremagic.com
          Reporter: nick@geany.org

The spec does not mention this: https://dlang.org/spec/function.html#postconditions

struct R
{
    bool empty(); // only logically const, not D const
}

R f() // returns a mutable R
out(r; r.empty) // Error: mutable method `R.empty` is not callable using a
`const` object
{
    R r; // not const
    return r;
}

For the above case, an `out` contract cannot be used. Note that inserting `assert(r.empty);` before the return statement does work.

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