# Reified Type Parameter

DevFeed: [Reified Type Parameter](<https://devfeed.tech/articles/reified-type-parameter-25021.md>)

Original publisher: [Read original article](<https://typealias.com/concepts/reified-type-parameter/>)

Author: author@typealias.com (Dave Leeds)

Published: 2017-10-07T03:42:19Z

Content type: tutorial

Language: en

Sources: [Dave Leeds on Kotlin - typealias.com](<https://devfeed.tech/sources/dave-leeds-on-kotlin-typealias-com.md>)

Topics: [Code](<https://devfeed.tech/topics/code.md>)

Tags: [cast](<https://devfeed.tech/tags/cast.md>), [class](<https://devfeed.tech/tags/class.md>), [code](<https://devfeed.tech/tags/code.md>), [examples](<https://devfeed.tech/tags/examples.md>), [extension-function](<https://devfeed.tech/tags/extension-function.md>), [function](<https://devfeed.tech/tags/function.md>), [generic](<https://devfeed.tech/tags/generic.md>), [kotlin](<https://devfeed.tech/tags/kotlin.md>), [programming](<https://devfeed.tech/tags/programming.md>), [property](<https://devfeed.tech/tags/property.md>), [reification](<https://devfeed.tech/tags/reification.md>), [reified-type-parameter](<https://devfeed.tech/tags/reified-type-parameter.md>), [type-parameter](<https://devfeed.tech/tags/type-parameter.md>), [types](<https://devfeed.tech/tags/types.md>), [variance](<https://devfeed.tech/tags/variance.md>)

## AI overview

An explanation of reified type parameters, including how they preserve type information in inline functions, support type checks and casts, and can provide class objects. The article covers single and multiple parameters, extension properties, requirements, alternatives, and code-size considerations.

## Source excerpt

Reified type parameters are type parameters that retain more characteristics of actual types than normal type parameters do. For a gentle introduction to the topic, check out the guide, Getting Real with Reified Type Parameters. Examples Single Parameter inline fun <reified T> Any.isInstanceOf(): Boolean = this is T Here we created an extension function to wrap the more common is operator. Why is this example so magical? Because normally, compiling this is T would result in an error since the type of T is erased.