Member "Address" not found or not visible after argument-dependent lookup in tuple(address,int16,int8,uint256,bool,int256,address)

Question

I am new to programming and trying to access a struct located in another smart contract but am receiving the following error.

"TypeError: Member "Address" not found or not visible after argument-dependent lookup in tuple(address,int16,int8,uint256,bool,int256,address). --> Auction.sol:45:23: | 45 | if(bid == r.users(i).Address) x = true;"

Is it possible to access structs in mappings of different contracts?

My code is as follows:

pragma solidity ^0.8.3;

contract Registry {
    
    mapping(int => User) public users;
    int8 public userCount = 0;
    
    struct User {
        address Address;
        int16 Longitude;
        int8 Latitude;
        uint Transformer_ID;
        bool Is_Prosumer;
        int Peak_Power;
        address Smart_Meter;
    }
    
    function addUser(int16 _longitude, int8 _latitude, uint  _transformerID, bool  _isProsumer, int _peakPower, address _smartMeter) public {
        users[userCount] = User(msg.sender, _longitude, _latitude, _transformerID, _isProsumer, _peakPower, _smartMeter);
        userCount ++;
    }
}

contract Auction {

    Registry r;
    address registryAddr;
    function RegistryRead(address addr) public {
        registryAddr = addr;
        r = Registry(r);
    }
    
    function verify(address addr, address bid) public returns (bool) {
        int i; bool x = false;
        
        int8 max = r.userCount();
        
        for(i = 0; i == max; i ++)
            if(bid == r.users(i).Address) x = true;
            
        return x;
    }
    
}

Answer 1

It's because when the Auction contract reads the users; it only gets data types of array and not the names you have used in Resigtry contract. Understand it like this;

uint => (address, int16, int8, uint, bool, int, address)

So Auction contract can not lookup Address.

Solution: You can use

(address userAddress,,,,,,) = r.users(i);
if(bid ==userAddress) {
    x = true;
}

Or alternatively; add a getUser function that explictly returs Users type:

contract Registry {
    
    mapping(int => User) public users;
    int8 public userCount = 0;   
    struct User {
        address Address;
        int16 Longitude;
        int8 Latitude;
        uint Transformer_ID;
        bool Is_Prosumer;
        int Peak_Power;
        address Smart_Meter;
    }
    
    function addUser(int16 _longitude, int8 _latitude, uint  _transformerID, bool  _isProsumer, int _peakPower, address _smartMeter) public {
        users[userCount] = User(msg.sender, _longitude, _latitude, _transformerID, _isProsumer, _peakPower, _smartMeter);
        userCount ++;
    }
    
    function getUser(int _id) public view returns(User memory) {
        return users[_id];
    }
}

contract Auction {

    Registry r;
   
    
    address registryAddr;
    function RegistryRead(address addr) public {
        registryAddr = addr;
        r = Registry(r);
    }
    
    function verify(address bid) public view returns (bool) {
        int i; bool x = false;
        int8 max = r.userCount();
       

        for(i = 0; i <= max; i ++) {
            if(bid == r.getUser(i).Address) {
                x = true;
            }
        }
            
        return x;
    }
    
}