It surely is, according to Apple's own documentation.
> Swift is a successor to the C, C++, and Objective-C languages. It includes low-level primitives such as types, flow control, and operators. It also provides object-oriented features such as classes, protocols, and generics.
If developers have such a big problem glueing C libraries into Java JNI, or Panama, then maybe game industry is not where they are supposed to be, when even Assembly comes to play.
> Swift is a successor to the C, C++, and Objective-C languages. It includes low-level primitives such as types, flow control, and operators. It also provides object-oriented features such as classes, protocols, and generics.
-- https://developer.apple.com/swift/
If developers have such a big problem glueing C libraries into Java JNI, or Panama, then maybe game industry is not where they are supposed to be, when even Assembly comes to play.