letclone

A procedural macro for convenient variable cloning in Rust.

Overview

letclone provides a clone! macro that simplifies the common pattern of cloning variables into new bindings. Instead of writing verbose let statements with .clone() calls, you can use the concise clone! macro.

Installation

Add this to your Cargo.toml:

[dependencies]
letclone = "0.1.0"

Usage

Basic Usage

use letclone::clone;

let original = String::from("hello");
clone!(original);
// Equivalent to: let original = original.clone();

Field Access

use letclone::clone;

struct Person {
    name: String,
}

let person = Person {
    name: String::from("Alice"),
};
clone!(person.name);
// Equivalent to: let name = person.name.clone();

assert_eq!(name, "Alice");

Method Call

use letclone::clone;

struct Container {
    value: String,
}

impl Container {
    fn get_value(&self) -> String {
        self.value.clone()
    }
}

let container = Container {
    value: String::from("test"),
};
clone!(container.get_value());
// Equivalent to: let get_value = container.get_value().clone();

assert_eq!(get_value, "test");

Mutable Bindings

Use the mut modifier to create mutable bindings:

use letclone::clone;

let original = String::from("hello");
clone!(mut original);
// Equivalent to: let mut original = original.clone();

original.push_str(" world");
assert_eq!(original, "hello world");

Multiple Expressions

Clone multiple variables in a single macro call:

use letclone::clone;

struct Data {
    field1: String,
    field2: String,
}

let data = Data {
    field1: String::from("a"),
    field2: String::from("b"),
};
let var = String::from("c");

clone!(data.field1, data.field2, var);
// Equivalent to:
// let field1 = data.field1.clone();
// let field2 = data.field2.clone();
// let var = var.clone();

assert_eq!(field1, "a");
assert_eq!(field2, "b");
assert_eq!(var, "c");

Supported Expression Types

Limitations

• Tuple index access (e.g., tuple.0) is not supported
• Only named fields and method calls are supported for expression derivation

License

This project is licensed under the Apache License 2.0 - see the LICENSE file for details.