openzeppelin-contracts/contracts/utils/Packing.sol

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.20;

/**
 * @dev Helper library packing and unpacking multiple values into bytes32
 */
library Packing {
    type Uint128x2 is bytes32;

    /// @dev Cast a bytes32 into a Uint128x2
    function asUint128x2(bytes32 self) internal pure returns (Uint128x2) {
        return Uint128x2.wrap(self);
    }

    /// @dev Cast a Uint128x2 into a bytes32
    function asBytes32(Uint128x2 self) internal pure returns (bytes32) {
        return Uint128x2.unwrap(self);
    }

    /// @dev Pack two uint128 into a Uint128x2
    function pack(uint128 first128, uint128 second128) internal pure returns (Uint128x2) {
        return Uint128x2.wrap(bytes32(bytes16(first128)) | bytes32(uint256(second128)));
    }

    /// @dev Split a Uint128x2 into two uint128
    function split(Uint128x2 self) internal pure returns (uint128, uint128) {
        return (first(self), second(self));
    }

    /// @dev Get the first element of a Uint128x2 counting from higher to lower bytes
    function first(Uint128x2 self) internal pure returns (uint128) {
        return uint128(bytes16(Uint128x2.unwrap(self)));
    }

    /// @dev Get the second element of a Uint128x2 counting from higher to lower bytes
    function second(Uint128x2 self) internal pure returns (uint128) {
        return uint128(uint256(Uint128x2.unwrap(self)));
    }
}