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<!--info-header-start--><h1>Readonly </h1><blockquote><p>by Anthony Fu <a href="https://github.com/antfu" target="_blank">@antfu</a></p></blockquote><p><a href="https://tsch.js.org/7/play" target="_blank"></a> &nbsp;&nbsp;&nbsp;<a href="./README.zh-CN.md" target="_blank"></a> <a href="./README.ja.md" target="_blank"></a> <a href="./README.ko.md" target="_blank"></a> <a href="./README.pt-BR.md" target="_blank"></a> </p><!--info-header-end-->

Implement the built-in Readonly<T> generic without using it.

Constructs a type with all properties of T set to readonly, meaning the properties of the constructed type cannot be reassigned.

For example:

ts
interface Todo {
  title: string
  description: string
}

const todo: MyReadonly<Todo> = {
  title: "Hey",
  description: "foobar"
}

todo.title = "Hello" // Error: cannot reassign a readonly property
todo.description = "barFoo" // Error: cannot reassign a readonly property
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