Helper methods to determine whether a type is TraitObject, Slice or Concrete, and work with them respectively.
assert_eq!(usize::METATYPE, MetaType::Concrete);
assert_eq!(any::Any::METATYPE, MetaType::TraitObject);
assert_eq!(<[u8]>::METATYPE, MetaType::Slice);
let a: Box<usize> = Box::new(123);
assert_eq!(Type::meta_type(&*a), MetaType::Concrete);
let a: Box<dyn any::Any> = a;
assert_eq!(Type::meta_type(&*a), MetaType::TraitObject);
let a = [123,456];
assert_eq!(Type::meta_type(&a), MetaType::Concrete);
let a: &[i32] = &a;
assert_eq!(Type::meta_type(a), MetaType::Slice);
let a: Box<dyn any::Any> = Box::new(123);
let meta: TraitObject = type_coerce(Type::meta(&*a));
println!("vtable: {:?}", meta.vtable);This currently requires Rust nightly for the ptr_metadata, specialization and arbitrary_self_types features.
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- Apache License, Version 2.0, (LICENSE-APACHE.txt or http://www.apache.org/licenses/LICENSE-2.0)
- MIT license (LICENSE-MIT.txt or http://opensource.org/licenses/MIT)
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