For iOS: Create array: NSArray *myCGPointArray = @[[NSValue valueWithCGPoint:CGPointMake(30.0, 150.0)],[NSValue valueWithCGPoint:CGPointMake(41.67, 145.19)]]; Get 1st CGPoint object: CGPoint myPoint = [myCGPointArray[0] CGPointValue];
Try the following public static bool IsBoxed<T>(T value) { return (typeof(T).IsInterface || typeof(T) == typeof(object)) && value != null && value.GetType().IsValueType; } By using a generic we allow the function to take into account both the type of the expression as viewed by the compiler and it’s underlying value. Console.WriteLine(IsBoxed(42)); // False Console.WriteLine(IsBoxed((object)42)); // True … Read more
No, there is no such method in the JDK. As it’s often the case, however, Apache Commons Lang provides such a method.
what is so hard technically to include primitive types when talking about Generics ? In Java’s case, it’s because of the way generics work. In Java, generics are a compile-time trick, that prevents you from putting an Image object into an ArrayList<String>. However, Java’s generics are implemented with type erasure: the generic type information is … Read more
It’s required to satisfy the verifiability constraints for the generated IL. Note that unverifiable doesn’t necessarily mean incorrect. It works just fine without the box instruction as long as its security context allows running unverifiable code. Verification is conservative and is based on a fixed rule set (like reachability). To simplify things, they chose not … Read more
An approach that might work is to write these two methods: public static void WithInt() { int x = 5; Console.WriteLine(x); } public static void WithVar() { var x = 5; Console.WriteLine(x); } Compile, and use ildasm to examine the produced CIL. Show your boss. edit @ck has done all but the last step for … Read more
There are two things going on: 1) The compiler treats “null” not as a null reference but as a null value… the null value for whatever type it needs to convert to. In the case of a Nullable<T> it’s just the value which has False for the HasValue field/property. So if you have a variable … Read more
It is all explained in the javadoc: Note that in most cases, for two instances of class Double, d1 and d2, the value of d1.equals(d2) is true if and only if d1.doubleValue() == d2.doubleValue() also has the value true. However, there are two exceptions: If d1 and d2 both represent Double.NaN, then the equals method … Read more
Jon’s point is true, but as a side note there is one slight exception to the rule; generics. If you have where T : ISomeInterface, then this is constrained, and uses a special opcode. This means the interface can be used without boxing. For example: public static void Foo<T>(T obj) where T : ISomeInterface { … Read more
The issue is that Integer.valueOf returns an Integer, not an int, but your someOtherMethod expects an int. Findbugs is basically warning you that you’re doing it a long-winded way that involves potentially creating an object (the Integer) that you don’t need which you’re then immediately going to unbox by passing it to someOtherMethod(int), e.g.: String … Read more