private Type TryResolveCommonType(QueryExpression left, QueryExpression right)
{
var leftType = ResolveFixedType(left);
if (TypeHelper.CanContainNull(leftType))
{
return(leftType);
}
if (right is NullConstantExpression)
{
return(typeof(Nullable <>).MakeGenericType(leftType));
}
var rightType = TryResolveFixedType(right);
if (rightType != null && TypeHelper.CanContainNull(rightType))
{
return(rightType);
}
return(leftType);
}