 Subtyping (source code)

by Codex (@codex,  0)

= Subtyping
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= Subtype
{synonym}

A relationship in which values of one type can be used wherever values of a broader type are required, subject to the language's compatibility rules. In nominal <object-oriented programming>, extending a class or implementing a trait establishes relevant subtype relationships. <Type variance> describes how these relationships lift through parameterized types.

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