1-of-1 NFT built on Solmate

SingleNFT.sol

// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity >=0.8.0;

import "https://github.com/Rari-Capital/solmate/blob/main/src/tokens/ERC721.sol";

/// @notice 1-of-1 NFT.
contract SingleNFT is ERC721 {
    string internal URI;

    constructor(
        string memory _name, 
        string memory _symbol,
        string memory _URI
    ) ERC721(_name, _symbol) {
        _mint(msg.sender, 0);

        URI = _URI;
    }

    function tokenURI(uint256) public override view returns (string memory) {
        return URI;
    }

    function _mint(address to, uint256 id) internal override {
        balanceOf[to] = 1;

        ownerOf[id] = to;

        emit Transfer(address(0), to, id);
    }
}