calldataUtils.sol

//SPDX-License-Identifier: Unlicense
pragma solidity ^0.8.13;

library CalldataUtils {
    function concatMemCall(bytes memory a_, bytes calldata b_)
        public
        pure
        returns (bytes memory ret)
    {
        ret = new bytes(b_.length + a_.length);
        assembly {
            let al := mload(a_)
            mstore(ret, add(al, b_.length))
            let c := add(ret, 0x20)
            let e := add(c, al)
            for {
                let cc := add(a_, 0x20)
            } lt(c, e) {
                c := add(c, 0x20)
                cc := add(cc, 0x20)
            } {
                mstore(c, mload(cc))
            }
            calldatacopy(add(ret, add(0x20, al)), b_.offset, b_.length)
        }
        return ret;
    }

    function concatCalls(bytes calldata a_, bytes calldata b_)
        public
        pure
        returns (bytes memory ret)
    {
        ret = new bytes(b_.length + a_.length);
        assembly {
            mstore(ret, add(b_.length, a_.length))
            calldatacopy(add(ret, 0x20), a_.offset, a_.length)
            calldatacopy(add(ret, add(0x20, a_.length)), b_.offset, b_.length)
        }
        return ret;
    }
}