public static DynamicMetaObject Restrict(this DynamicMetaObject self, Type type)
{
ContractUtils.RequiresNotNull(self, nameof(self));
ContractUtils.RequiresNotNull(type, nameof(type));
if (self is IRestrictedMetaObject rmo)
{
return(rmo.Restrict(type));
}
if (type == self.Expression.Type)
{
if (type.IsSealed() ||
self.Expression.NodeType == ExpressionType.New ||
self.Expression.NodeType == ExpressionType.NewArrayBounds ||
self.Expression.NodeType == ExpressionType.NewArrayInit)
{
return(self.Clone(self.Restrictions.Merge(BindingRestrictionsHelpers.GetRuntimeTypeRestriction(self.Expression, type))));
}
}
if (type == typeof(DynamicNull))
{
return(self.Clone(
AstUtils.Constant(null),
self.Restrictions.Merge(BindingRestrictions.GetInstanceRestriction(self.Expression, null))
));
}
Expression converted;
// if we're converting to a value type just unbox to preserve
// object identity. If we're converting from Enum then we're
// going to a specific enum value and an unbox is not allowed.
if (type.IsValueType() && self.Expression.Type != typeof(Enum))
{
converted = Expression.Unbox(
self.Expression,
CompilerHelpers.GetVisibleType(type)
);
}
else
{
converted = AstUtils.Convert(
self.Expression,
CompilerHelpers.GetVisibleType(type)
);
}
return(self.Clone(converted, self.Restrictions.Merge(BindingRestrictionsHelpers.GetRuntimeTypeRestriction(self.Expression, type))));
}
public DynamicMetaObject Restrict(Type type)
{
if (type == LimitType)
{
return(this);
}
if (HasValue)
{
return(new RestrictedMetaObject(
AstUtils.Convert(Expression, type),
BindingRestrictionsHelpers.GetRuntimeTypeRestriction(Expression, type),
Value
));
}
return(new RestrictedMetaObject(
AstUtils.Convert(Expression, type),
BindingRestrictionsHelpers.GetRuntimeTypeRestriction(Expression, type)
));
}
