Merge multiple source into one destination

[Chaosflo]

Is your feature request related to a problem? Please describe.
We started to transfer from AutoMapper to Mapperly.
Sometimes we use the merging feature, means we have two objects which we want to merge into one.

public class SourceA
{
	public string A { get; set; }

	public string B { get; set; }
}

public class SourceB
{
	public string C { get; set; }

	public string D { get; set; }
}

public class Destination
{
	public required string A { get; init; }

	public required string B { get; init; }

	public required string C { get; init; }

	public required string D { get; init; }
}

As you see I have SourceA and SourceB and I have Destination class.
Also you see that SourceA contains different properties than SourceB.
The required init is place there on purpose.

Currently I have not found any solutions to this.

Describe the solution you'd like
I would like to do something like this with additional parameters which is already existing

public static partial Destination ToDestination(this SourceA sourceA, [MapAdditionalSource]SourceB sourceB);

Describe alternatives you've considered
I am open to any api, if it solves the problem.
Changing the required to non required is not an option

Additional context
Add any other context or screenshots about the feature request here.

[latonz]

This is not yet possible in Mapperly. You could provide members C and D as additional arguments, but this is probably not what you want. Feel free to implement this in a PR. A good starting point to contribute is the contributors documentation. Please let us know if you plan to work on this 😊