I need to generically process a map containing a list, but can’t get by the compiler warning. It doesn’t make sense why I can generically process the list, but not the map. From the below code, why does the compiler allow the ‘processList’ method call, but not the call to ‘processMap’? It doesn’t seem to… Read More Why does Java complain about use of generics in map but not list?
I need to write a generic method in the non-generic class. My code looks like the following: public record Test<T>(T value); public class MyClass { public <T> Test<T> getRecord() { // some method logic … switch(type) { case 1: return new Test<String>("my string"); // not compile … default: return new Test<Integer>(5); //not compile } }… Read More How can I write a generic method?
I have a function that can apply to multiple situation. For example, I have a function f that contains another function h, which can apply different function depend on the situation. def f(n): return n.cost + h(n) and the h function will be determine before runtime. I understand that I could just use f(n, h)… Read More Does python have template equivalent method like C++?
I’m confused as to why the definitions of doSomething1() and doSomething2() are not treated equally? class Example< TypeA = void, TypeB = void, ArgsType = { valueA?:TypeA, valueB?:TypeB } > { valueA?:TypeA; valueB?:TypeB; constructor( valueA:TypeA, valueB:TypeB ) { this.valueA = valueA; this.valueB = valueB; } doSomething1( args: { valueA?:TypeA, valueB?:TypeB } ) { // this… Read More How can I move a generic TS argument definition without getting the "Property doesn't exist on type 'unknown'" error?
I want to: return a generic type, can be for example ICollection OR string, needs to be flexible. this will be returned by the restapi client that consumes the api.(different endpoints have different return types) pass in some kind of delegate containing the method to be called from the actual rest client. rest client is… Read More Method to return a generic type when passing in a generic delegate
I know this maybe be a duplicate but i’ve been scouring through stack overflow but i’m still yet to find an answer. What i want to do is accept a class type as argument and return an instance of that class. Here is what i’m trying to do class A { } class B {… Read More Receive class type and argument and return instance
Assum I have this extension function: inline fun <reified R> Any.getPrivateProperty(variableName: String): R { … } I can quite conveniently call this with something like s.getPrivateProperty<Int>("height"), an expression that is of type Int. Now I wanted to make sure the function is only defined on non-optional types. I used the definitely-not-nullable notation: inline fun <T:… Read More Can I mix inferred and exlicit generic type parameters in Kotlin?
I want a reference to a delegate that returns an instance of a generic interface, where the type parameter is covariant. If I specify the type of T when calling Get then it compiles ok. But within Get, I can’t make what looks like an equivalent assignment – despite T being constrained to IItem. It… Read More Why doesn't this C# generic delegate assign?
I’m trying to write a function which converts a byte array of JSON string to another in accordance with the type parameter of the return value as the following rule: map[string]interface{}: convert to map[string]interface{} []byte: no conversion, return as is struct: convert to the struc My code is as follow: func GetJsonData[T any](jsonByteArray []byte) (result… Read More How to convert known type to pointer to type parameter in a switch?
Suppose we have generic classes G1<T> and G2<T>: G1<T>. And classes C1 and C2: C1. Of the following which is not true?: G2<C1> is-a G1<C1>, G1<C2> is-a G1<C1>, G2<C2> is-a G1<C1> Aside from these is there any case that would surprise intuition? >Solution : It is easy to check: Console.WriteLine(new G2<C1>() is G1<C1>); // True… Read More Is-a relationships in Generics