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Why Pin is difficult to use

• Pin<Ptr> is "just" a type defined in the standard library
• This satisfied the needs of its original audience, the creators of async runtimes, without needing to extending the core language
• That audience could accept some of its ergonomic downsides, as users of async would rarely interact with Pin directly

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"You might wonder why Pin is so awkward to use. The answer is largely historical."

"Pin<Ptr> offered a simpler implementation for the Rust project than alternatives".

"Pin was designed primarily for the ~100 people in the world who write async runtimes. The Rust team chose a simpler (for the compiler) but less ergonomic design."

"More user-friendly proposals existed but were rejected as too complex for the primary audience, who could handle the complexity."

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