How can I write this generic function with a arrow function ?
function simpleState<T>(initial: T): [() => T, (v: T) => void] {
let value: T = initial;
return [
() => value,
(v: T) => {
value = v;
}
]
};
const simpleState = <T>(initial: T): [() => T, (v: T) => void] => {
// same function body as before
}
Since you tagged react-native, be aware that in a .tsx file, this will probably not work, since the <T> will be parsed as being a JSX tag. You can either put it in a .ts file, and import it into a .tsx file, or use one of the following workarounds to get it to not be interpreted as a JSX element.
Trailing comma:
<T,>(initial: T): // etc
Extend from unknown:
<T extends unknown>(initial: T): // etc
const simpleState2 = <T>(initial: T): [() => T, (v: T) => void] => {
let value: T = initial;
return [
() => value,
(v: T) => {
value = v;
},
];
}