https://issues.dlang.org/show_bug.cgi?id=19619

          Issue ID: 19619
           Summary: Temporary solution for attribute extensibility problem
           Product: D
           Version: D2
          Hardware: All
               URL: https://forum.dlang.org/thread/qnrkfiqmtqzpyocxxtsk@fo
                    rum.dlang.org
                OS: All
            Status: NEW
          Keywords: spec
          Severity: enhancement
          Priority: P1
         Component: dmd
          Assignee: nobody@puremagic.com
          Reporter: dfj1esp02@sneakemail.com

Given difficulties with adding compiler recognized attributes as seen in
DIP1017, how about temporarily reserving UDAs with certain naming convention as
keywords (like @safe)? Because they have usual UDA syntax, their status as
keywords can be lifted later (ldc and gdc already implement compiler recognized
UDAs).
Possible naming conventions:
1. Prefix 'd', e.g. @dnoreturn
2. Prefix '_', e.g. @_noreturn or @_noreturn_
3. Prefix 'core', e.g. @core_noreturn
Declared like
---
module core.attribute;
struct noreturn { bool enabled; }
alias noreturn _noreturn_;
---
Compiler should create normal UDAs for them to verify that specified symbols
are visible (declared in core.attribute).
Can this simplify language extensibility?

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