This is the narrowed down code from my actual use case. function wrapMe<F extends (…args: any) => any>( f: F, ): (…args: Parameters<F>) => ReturnType<F> { return function(…args: Parameters<F>): ReturnType<F> { return f(…args); // ^^^^ // Type ‘Parameters<F>’ must have a ‘[Symbol.iterator]()’ method that returns an iterator. [2488] } } Why is this a typescript… Read More typescript error when spreading `Parameters<F>`

Why does this code print Array(7) [ <7 empty slots> ] (or an array of undefined, 7 times) instead of an array with the single element 7? const a = [ 7 ]; console.log(new Array(…a)); >Solution : new Array(…a) is the same as saying new Array(7), which will create an empty array with 7 undefined… Read More Why does `new Array(…[ 7 ])` produce `Array(7) [ <7 empty slots> ]`?

can you do this in C++: vector<int> v1={1,2}, v2={3,4}; vector<int> v3={…v1, …v2, 5}; //v3 = {1,2,3,4,5} What is the simplest way to do this with C++ ? >Solution : No spread operator in C++. Probably the simplest way would be a sequence of inserts std::vector<int> v3; v3.insert(v3.end(), v1.begin(), v1.end()); v3.insert(v3.end(), v2.begin(), v2.end()); v3.insert(v3.end(), 5); Various… Read More does C++ have spread operator?

I am new to TypeScript and I am going to change my project to TypeScript. But I got some error. I have searched about the spread arguments but I can’t figure it out correctly. This is I tried so far. export const fetcher = async (…args) => { return fetch(…args).then(async (res) => { let payload;… Read More A spread argument must either have a tuple type or be passed to a rest parameter

I have this really simple variadic function that cycle through its arguments and adds a string "Transformed" to them. function Transform(…children) { return children.map(child=> child + ” Transformed”) } document.write( Transform( Transform(” test1″, ” test2″), //only test2 gets double transformed Transform(” test3″) //here the first argument gets double transformed though ) ) For some strange… Read More Javascript first argument gets ignored in nested functions with spread arguments

app.js let ids = [1, 2, 3]; let obj = {}; for (let i in ids) { obj = { …obj, ids[i]: "" }; } console.log(obj); While executing the above code, I get the below error. Parsing error: Unexpected token, expected "," 4 | 5 | for (let i in ids) { > 6 |… Read More Parsing error: Unexpected token, expected "," AND SyntaxError: Unexpected token '['