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kotlinlang

How bad is it to use `@OptIn(ExperimentalContracts::class)` in a library? Looks like `contracts {}` blocks do not generate any bytecode (besides metadata?) so as long as it's only used internally it should be fine?

it is used by stdlib in all places, I guess the only problem is you will have to refactor the implementation when they finish the contracts API (if it changed)

Yeah, <https://github.com/Kotlin/KEEP/blob/master/proposals/kotlin-contracts.md#compatibility-notice|the KEEP says contracts are pretty much binary stable>:
• _Syntax for declaring contracts_ (i.e. Contracts DSL) is unstable at the moment, and it's possible that it will be completely changed in the future.
    ◦ It means that writing your own contracts isn't suited for production usage yet
• _Binary representation_ (in Kotlin Metadata) is stable enough and actually is a part of stdlib already. It won't be changed without a graceful migration cycle.
    ◦ It means that you can depend on binary artifacts with contracts (e.g. stdlib) with all usual compatibility guarantees
• _Semantics_, as usual, may be changed only in exceptional circumstances and only after graceful migration cycle
    ◦ It means that you can rely on the analysis made with the help of contracts, as it won't get broken suddenly