247 An option to exclude null values from serialization Custom class discriminators in polymorphic serialization Learn more in the changelog. What's new in Kotlin 1.5.20 Released: 24 June 2021 out of the scope of this document. Language and stdlib Forbid spread operator in signature-polymorphic calls Forbid non-abstract classes containing abstract members invisible from that classes (in type: source Short summary: Kotlin 1.5 will outlaw the use of spread operator (*) on signature-polymorphic calls Deprecation cycle: < 1.5: introduce warning for the problematic operator at call-site

default values An option to exclude null values from serialization Custom class discriminators in polymorphic serialization Learn more in the changelog. Kotlin 1.5.20 的新特性 发布于：2021-06-24 Kotlin 1.5.20 signature-polymorphic calls Issue: KT-35226 Component: Core language Incompatible change type: source Short summary: Kotlin 1.5 will outlaw the use of spread operator (*) on signature-polymorphic calls embers can be used to temporarily revert to pre-1.4 behavior Changed behavior of signature-polymorphic calls to methods with a single vararg parameter to avoid wrapping the argument into another array

default values An option to exclude null values from serialization Custom class discriminators in polymorphic serialization Learn more in the changelog. Kotlin 1.5.30 250 Kotlin 1.5.20 的新特性 发布于：2021-06-24 signature-polymorphic calls Issue: KT-35226 Component: Core language Incompatible change type: source Short summary: Kotlin 1.5 will outlaw the use of spread operator (*) on signature-polymorphic calls mbers can be used to temporarily revert to pre- 1.4 behavior Changed behavior of signature-polymorphic calls to methods with a single vararg parameter to avoid wrapping the argument into another array