Solidity Error: Version 0.8.0 : Struct containing a (nested) mapping cannot be constructed - struct

Question

struct Campaign {
address payable campaignOwner;
string campaignTitle;
string campaignDescription;
uint256 goalAmount;
uint256 totalAmountFunded;
uint256 deadline;
bool goalAchieved;
bool isCampaignOpen;
bool isExists;
mapping(address => uint256) contributions;
}
//stores a Campaign struct for each unique campaign ID.
mapping(uint256 => Campaign) campaigns;
function createCampaign(string memory _campaignTitle, string memory _campaignDescription, uint256 _goalAmount, uint256 _fundingPeriodInDays ) public {
++totalCampaigns;
uint256 period = block.timestamp + (_fundingPeriodInDays * 1 days);
Campaign memory aCampaign = Campaign(payable(msg.sender),_campaignTitle, _campaignDescription, _goalAmount, 0, period , false, true, true);
campaigns[totalCampaigns] = aCampaign;
}
I am using Solc version 0.8.0. When I try to create a Struct that contains mapping, I received an error:
Struct containing a (nested) mapping cannot be constructed.
When I use older versions of solc (0.5.8), the code compiles without problems. But this version is not supported with other solidity files and giving error as:
Source file requires different compiler version (current compiler is
0.8.13+commit.abaa5c0e.Emscripten.clang) - note that nightly builds are considered to be strictly less than the released version

Answer 1

You can not keep a struct containing a mapping in memory, and you can not initialize a storage object in a function, it must be a state variable. So what you can do is, get an object from your mapping, assign it to a local variable and modify it. Like this:
function createCampaign(string memory _campaignTitle, string memory _campaignDescription, uint256 _goalAmount, uint256 _fundingPeriodInDays ) public {
++totalCampaigns;
uint256 period = block.timestamp + (_fundingPeriodInDays * 1 days);
Campaign storage aCampaign = campaigns[totalCampaigns];
aCampaign.campaignOwner = payable(msg.sender);
aCampaign.campaignTitle = _campaignTitle;
aCampaign.campaignDescription = _campaignDescription;
aCampaign.goalAmount = _goalAmount;
aCampaign.totalAmountFunded = 0;
aCampaign.deadline = period;
aCampaign.goalAchieved = false;
aCampaign.isCampaignOpen = true;
aCampaign.isExists = true;
}