define_opaque in std::prelude::v1 - Rust
Description: Provide a list of type aliases and other opaque-type-containing type definitions to an item with a body. This list will be used in that body to define opaque types’ hidden types. Can only be applied to things that have bodies.

## define_opaque

# Attribute Macro define_opaque

Source

    #[define_opaque]

🔬This is a nightly-only experimental API. (`type_alias_impl_trait` #63063)
Expand description

Provide a list of type aliases and other opaque-type-containing type definitions to an item with a body. This list will be used in that body to define opaque types’ hidden types. Can only be applied to things that have bodies.