4 ms·

That's true. A talented C# dev will need to know co/contravariance as well as implicits considering they also exist in C#. In Scala, being familiar with these

• hokkos 12y ago
  Can you give me examples of implicits in C# ? I am unable to see a parallel.
  • jakevn 12y ago
    using System; public class Program { public class Person { private string _name; private int _age; public Person(string name, int age) { _name = name; _age = age; } public static implicit operator int(Person p) { return 42; } } public static void Main() { var person = new Person("Jim", 51); var number = 100; AdditionPrinter(person, number); // Prints 142 } public static void AdditionPrinter(int a, int b) { Console.WriteLine(a + b); } }
    • seanmcdirmid 12y ago
      Also consider extension methods, which serve some of the same purpose as implicits in Scala.
• dragonwriter 12y ago
  > A talented C# dev will need to know co/contravariance as well as implicits considering they also exist in C#. True for co/contravariance. For implicits, that depends on which implicits you are talking about. Scala has: * implicit conversion operators (these have existed in C# for some time, under the same name) * implicit parameters (C# doesn't have an analog to these that I can think of) * implicit classes (C# has an analog in classes providing extension methods, though the classes themselves are distinguished by a keywords as they are in Scala; in Scala, these are essentially syntactic sugar for creating a normal class and an implicit conversion from the extended class.)
  • jakevn 12y ago
    > implicit parameters (C# doesn't have an analog to these that I can think of) C# allows default values for parameters, but it's not quite the same. Example of C# default value for parameter: static void Addition(int a, int b = 42) { Console.WriteLine(a + b); } Addition(4); // Prints 46 Addition(4, 5); // Prints 9 In Scala, the default (implicit) value has more complex rules. Like C#, implicit parameters must come after non-implicit parameters (if any). Unlike C#, the implicit value does not need to be defined in the signature. Also unlike C#, if you provide the value for one implicit parameter, you must provide the value for all implicit parameters.
    • dragonwriter 12y ago
      > C# allows default values for parameters, but it's not quite the same. Right. Scala has C#-style default parameters as well, implicit parameters are a different (though very loosely related) thing.