https://issues.dlang.org/show_bug.cgi?id=20540

          Issue ID: 20540
           Summary: (White|Black)Hole does not work with return|scope
                    functions
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: normal
          Priority: P1
         Component: phobos
          Assignee: nobody@puremagic.com
          Reporter: moonlightsentinel@disroot.org

White/BlackHole does not generate correct function signatures for functions annotated with return/scope:

------------------------------------

import std.typecons;

interface I
{
    I foo() return scope;
}

void main()
{
    scope i = new BlackHole!I();
    i.foo();
}

------------------------------------

/dlang/dmd/linux/bin64/../../src/phobos/std/typecons.d-mixin-4543(4544): Error:
function I std.typecons.AutoImplement!(I, generateEmptyFunction,
isAbstractFunction).AutoImplement.foo() does not override any function, did you
mean to override scope I onlineapp.I.foo() return?
/dlang/dmd/linux/bin64/../../src/phobos/std/typecons.d(4315): Error: template
instance std.typecons.AutoImplement!(I, generateEmptyFunction,
isAbstractFunction) error instantiating
onlineapp.d(10):        instantiated from here: BlackHole!(I)

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