User-defined operator

Why use this example

Use this pattern to test contract composition, external calls, events, and return values inside one reproducible run. The entry isolates user-defined operator so its input, result, and state changes stay easy to compare.

Solidity to run

import "./Price.sol"
Price subtotal = Price.wrap(20)
Price fee = Price.wrap(2)
Price total = subtotal + fee
Price.unwrap(total)

Official Solidity reference

Compare this focused investigation with the complete language definition in the Solidity documentation.

Included local files

Solidity REPL creates these files before compiling the main entry, so its imports resolve without additional setup.

// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.19;

type Price is uint256;

function addPrice(Price left, Price right) pure returns (Price) {
  return Price.wrap(Price.unwrap(left) + Price.unwrap(right));
}

using { addPrice as + } for Price global;

What to expect

The globally attached plus operator combines the wrapped Price values and unwraps to 22.

Continue the investigation

Change a value, add another expression, or open Inspect after the run. Accepted entries remain available to the next entry, and the clean replay keeps the complete result reproducible.