Inheritance from Rust’s Perspective

// Copyright 2025 Google LLC
// SPDX-License-Identifier: Apache-2.0

// Data
pub struct Data {
    id: usize,
    name: String,
}

// Concrete behavior
impl Data {
    fn new(id: usize, name: impl Into<String>) -> Self {
        Self { id, name: name.into() }
    }
}

// Abstract behavior
trait Named {
    fn name(&self) -> &str;
}

// Instanced behavior
impl Named for Data {
    fn name(&self) -> &str {
        &self.name
    }
}

From Rust’s perspective, one where Inheritance was never there, introducing inheritance would look like muddying the water between types and traits.
A type is a concrete piece of data and its associated behavior.

A trait is abstract behavior that must be implemented by a type.

A class is a combination of data, behavior, and overrides to that behavior.
Coming from Rust, an inheritable class looks like a type that is also a trait.
This is not an upside, as we can no longer reason about concrete types.
Without being able to separate the two, it becomes difficult to reason about generic behavior vs concrete specifics, because in OOP these two concepts are tied up in each other.
The convenience of flat field access and DRY in type definitions is not worth the loss in specificity between writing code that delineates between behavior and data.

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Inheritance from Rust’s Perspective