Try improve typing

src/vs/platform/quickinput/common/quickInput.ts

@@ -177,6 +177,8 @@ export interface IQuickInputButton {
 
 export const IQuickInputService = createDecorator<IQuickInputService>('quickInputService');
 
+export type Omit<T, K extends keyof T> = Pick<T, Exclude<keyof T, K>>;
+
 export interface IQuickInputService {
 
 	_serviceBrand: any;
@@ -184,7 +186,9 @@ export interface IQuickInputService {
 	/**
 	 * Opens the quick input box for selecting items and returns a promise with the user selected item(s) if any.
 	 */
-	pick<T extends IQuickPickItem, O extends IPickOptions<T>>(picks: TPromise<T[]> | T[], options?: O, token?: CancellationToken): TPromise<O extends { canPickMany: true } ? T[] : T>;
+	pick<T extends IQuickPickItem>(picks: TPromise<T[]> | T[], options?: IPickOptions<T> & { canPickMany: true }, token?: CancellationToken): TPromise<T[]>;
+	pick<T extends IQuickPickItem>(picks: TPromise<T[]> | T[], options?: IPickOptions<T> & { canPickMany: false }, token?: CancellationToken): TPromise<T>;
+	pick<T extends IQuickPickItem>(picks: TPromise<T[]> | T[], options?: Omit<IPickOptions<T>, 'canPickMany'>, token?: CancellationToken): TPromise<T>;
 
 	/**
 	 * Opens the quick input box for text input and returns a promise with the user typed value if any.