[Issue 20868] DIP1000: scope delegate triggers error in unsafe code and it shouldn't

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=20868

--- Comment #5 from Walter Bright <bugzilla at digitalmars.com> ---
To be specific, when compiled with -dip1000:

  void scoped (scope void delegate() dg) {
    static void delegate()[] dgs;
    dgs ~= dg;  // Error: scope variable `dg` may not be copied into allocated
memory
  }

and there is no error without -dip1000.

The first thing to do is simplify:

  void scoped (scope void* p) {
    static void*[] px;
    px ~= p;
  }

which exhibits the same behavior. But let's try this:

  void scoped (scope void* p) {
    static void* px;
    px = p;
  }

which generates no error with or without -dip1000. Marking the function with
@safe yields:

   Error: scope variable p is assigned to non-scope px

with or without -dip1000.

The examples must behave the same way. They don't, so which is right? The array
examples are wrong.

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