+function promisify2<T, U, A> (func: (arg1: T, arg2: U, cb: (err: any, result: A) => void) => void): (arg1: T, arg2: U) => Promise<A> {
+ return function promisified (arg1: T, arg2: U): Promise<A> {
+ return new Promise<A>((resolve: (arg: A) => void, reject: (err: any) => void) => {
+ func.apply(null, [ arg1, arg2, (err: any, res: A) => err ? reject(err) : resolve(res) ])
+ })
+ }
+}
+
+function promisify2WithVoid<T, U> (func: (arg1: T, arg2: U, cb: (err: any) => void) => void): (arg1: T, arg2: U) => Promise<void> {
+ return function promisified (arg1: T, arg2: U): Promise<void> {
+ return new Promise<void>((resolve: () => void, reject: (err: any) => void) => {
+ func.apply(null, [ arg1, arg2, (err: any) => err ? reject(err) : resolve() ])
+ })
+ }
+}
+
+const readFileBufferPromise = promisify1<string, Buffer>(readFile)
+const unlinkPromise = promisify1WithVoid<string>(unlink)
+const renamePromise = promisify2WithVoid<string, string>(rename)
+const writeFilePromise = promisify2WithVoid<string, any>(writeFile)
+const readdirPromise = promisify1<string, string[]>(readdir)
+const mkdirpPromise = promisify1<string, string>(mkdirp)
+const pseudoRandomBytesPromise = promisify1<number, Buffer>(pseudoRandomBytes)
+const createPrivateKey = promisify1<number, { key: string }>(pem.createPrivateKey)
+const getPublicKey = promisify1<string, { publicKey: string }>(pem.getPublicKey)
+const bcryptComparePromise = promisify2<any, string, boolean>(bcrypt.compare)
+const bcryptGenSaltPromise = promisify1<number, string>(bcrypt.genSalt)
+const bcryptHashPromise = promisify2<any, string | number, string>(bcrypt.hash)
+const createTorrentPromise = promisify2<string, any, any>(createTorrent)
+const rimrafPromise = promisify1WithVoid<string>(rimraf)
+const statPromise = promisify1<string, Stats>(stat)
+