<:< operator in scala

Question

Can anybody provide some details on <:< operator in scala. I think:

if(apple <:< fruit)  //checks if apple is a subclass of fruit.

Are there any other explanations? I see many definitions in the scala source file.

question from:https://stackoverflow.com/questions/2603003/operator-in-scala

Answer 1

<:< is not an operator - it is an identifier and is therefore one of:

• the name of a type (class, trait, type alias etc)
• the name of a method/val or var

In this case, <:< appears twice in the library, once in Predef as a class and once as a method on Manifest.

For the method on Manifest, it checks whether the type represented by this manifest is a subtype of that represented by the manifest argument.

For the type in Predef, this is relatively new and I am also slightly confused about it because it seems to be part of a triumvirate of identical declarations!

class <%<[-From, +To] extends (From) ? To
class <:<[-From, +To] extends (From) ? To
class =:=[From, To] extends (From) ? To