//! MMTk uses [`crate::vm::VMBinding`], which allows us to call into bindings
//! with little overhead. As a result, some types in MMTk are generic types with a type parameter `<VM>`.
//! However, in some cases, using generic types is not allowed. For example, in an object-safe trait,
//! the methods cannot be generic, thus the method's parameters cannot be generic types.
//!
//! This module defines macros that can be used to create a special ref type that erases the <VM> type parameter.
//! For example, we create a type `TErasedRef` for `&T<VM>`. `TErasedRef` has no type parameter, and
//! can be used in places where a type parameter is undesired. The type `TErasedRef` can be cast back to `&T<VM>`
//! when we supply a type parameter `<VM>`. This works under the assumption that
//! one MMTk process should only have one VM type. In such a case, when we cast from a `&T<VM>` to `TErasedRef`, and
//! cast back to `&T<VM>`, the type parameter is guaranteed to be the same. Thus the casting is correct.
//!
//! `TErasedRef` has the same lifetime as `&T<VM>`.
pub use define_erased_vm_mut_ref;