Module std::marker

1.0.0 · source ·
Expand description

Primitive traits and types representing basic properties of types.

Rust types can be classified in various useful ways according to their intrinsic properties. These classifications are represented as traits.


  • Zero-sized type used to mark things that “act like” they own a T.
  • A marker type which does not implement Unpin.


  • Types whose values can be duplicated simply by copying bits.
  • Types that can be transferred across thread boundaries.
  • Types with a constant size known at compile time.
  • Types for which it is safe to share references between threads.
  • Types that do not require any pinning guarantees.
  • ConstParamTyExperimental
    A marker for types which can be used as types of const generic parameters.
  • DestructExperimental
    A marker for types that can be dropped.
  • DiscriminantKindExperimental
    Compiler-internal trait used to indicate the type of enum discriminants.
  • FnPtrExperimental
    A common trait implemented by all function pointers.
  • FreezeExperimental
    Used to determine whether a type contains any UnsafeCell internally, but not through an indirection. This affects, for example, whether a static of that type is placed in read-only static memory or writable static memory. This can be used to declare that a constant with a generic type will not contain interior mutability, and subsequently allow placing the constant behind references.
  • PointerLikeExperimental
    A marker for pointer-like types.
  • Required trait for constants used in pattern matches.
  • TupleExperimental
    A marker for tuple types.
  • UnsizeExperimental
    Types that can be “unsized” to a dynamically-sized type.

Derive Macros§

  • Derive macro generating an impl of the trait Copy.
  • ConstParamTyExperimental
    Derive macro generating an impl of the trait ConstParamTy.