Specified.cs

void Main()
{
	Mapper.Initialize(cfg=>
	{
		cfg.CreateMap<object, bool>().ConvertUsing(o=>o!=null);
		cfg.RecognizeDestinationPostfixes("Specified");
	});

	Mapper.AssertConfigurationIsValid();
	
	Mapper.Map<Destination>(new Source { Value = 0 }).Dump();
	Mapper.Map<Destination>(new Source { Value = 13 }).Dump();
	Mapper.Map<Destination>(new Source { Value = null }).Dump();
}

class Source
{
	public int? Value { get; set; }
}

class Destination
{
	public int Value { get; set; }
	public bool ValueSpecified { get; set; }
}