Primitives

Types like i8, u8, i16, u16, i32, u32, i64, u64, isize, usize, i128, u128 will be converted to int or BigInt depending on whether they fit in the integer.

In addition, the #[frb(type_64bit_int)] can be utilized to force the 64bit types to be integers.

For other types like f32, f64, bool, String, please refer to the simple correspondence table for the mapping.