constraints

In C# we can define a generic type that imposes constraints on the types that can be used as the generic parameter. The following example illustrates the usage of generic constraints: interface IFoo { } class Foo<T> where T : IFoo { } class Bar : IFoo { } class Simpson { } class Program { static void Main(string[] args) { Foo<Bar> a = new Foo<Bar>(); Foo<Simpson> b = new Foo<Simpson>(); // error CS0309 } } Is there a way we can impose constraints for template parameters in C++. C++0x has native support for this but I am talking about current standard C++. luke As someone else has mentioned, C+

I know that a lot people already asked tons of questions about this, but even with the answers I can't make it work. When I'm dealing with constraints on storyboard, it's easy but in code I have a hard time. I try, for example, to have a view that stays on the right side and has the height of the screen according the screen orientation. This is my code: UIView *myView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 200, 748)]; myView.backgroundColor = [UIColor redColor]; [self.view addSubview:myView]; [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-[myView(>

I'm looking for a way to temporarily turn off all DB's constraints (eg table relationships). I need to copy (using INSERTs) one DB's tables to another DB. I know I can achieve that by executing commands in proper order (to not break relationships). But it would be easier if I could turn off checking constraints temporarily and turn it back on after the operation's finish. Is this possible? gbn You can disable FK and CHECK constraints only in SQL 2005+ . See ALTER TABLE ALTER TABLE foo NOCHECK CONSTRAINT ALL or ALTER TABLE foo NOCHECK CONSTRAINT CK_foo_column Primary keys and unique constraints

I would like to differentiate between following cases: A plain value type (e.g. int ) A nullable value type (e.g. int? ) A reference type (e.g. string ) - optionally, I would not care if this mapped to (1) or (2) above I have come up with the following code, which works fine for cases (1) and (2): static void Foo<T>(T a) where T : struct { } // 1 static void Foo<T>(T? a) where T : struct { } // 2 However, if I try to detect case (3) like this, it does not compile: static void Foo<T>(T a) where T : class { } // 3 The error message is Type 'X' already defines a member called 'Foo' with the same

How do I create a unique constraint on an existing table in SQL Server 2005? I am looking for both the TSQL and how to do it in the Database Diagram. The SQL command is: ALTER TABLE <tablename> ADD CONSTRAINT <constraintname> UNIQUE NONCLUSTERED ( <columnname> ) See the full syntax here . If you want to do it from a Database Diagram: right-click on the table and select 'Indexes/Keys' click the Add button to add a new index enter the necessary info in the Properties on the right hand side: the columns you want (click the ellipsis button to select) set Is Unique to Yes give it an appropriate