Latest revision as of 00:36, 10 September 2021

External

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+=External=
+* https://docs.oracle.com/javase/tutorial/java/generics/
+* https://docs.oracle.com/javase/tutorial/extra/generics/index.html
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 * [[Java#Java_5|Java]]
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 * [[Java Generics Concepts|Concepts]]
 * [[Java Generics Programming Model|Programming Model]]
-=Organizatorium=
-====Covariance====
-{{External|https://en.wikipedia.org/wiki/Covariance_and_contravariance_(computer_science)}}
-Let T and S be two types (class or function types), such that S is a subtype of T. If method m of T is overridden in S, then the corresponding types from the m's signature can either preserve the relationship between T and S (the type used in S is a subtype of the corresponding type in T), reverse the relationship (the type used in S is a super type of the type used in T), or neither preserve nor reverse this relationship. If they preserve the relationship to T and S, we say they are covariant, if they reverse the relationship of T and S, we say they are contravariant.