=== tests/cases/compiler/promiseTypeInference.ts ===
declare class Promise<T> {
>Promise : Promise<T>
>T : T

    then<U>(success?: (value: T) => Promise<U>): Promise<U>;
>then : <U>(success?: (value: T) => Promise<U>) => Promise<U>
>U : U
>success : (value: T) => Promise<U>
>value : T
>T : T
>Promise : Promise<T>
>U : U
>Promise : Promise<T>
>U : U
}
interface IPromise<T> {
>IPromise : IPromise<T>
>T : T

    then<U>(success?: (value: T) => IPromise<U>): IPromise<U>;
>then : <U>(success?: (value: T) => IPromise<U>) => IPromise<U>
>U : U
>success : (value: T) => IPromise<U>
>value : T
>T : T
>IPromise : IPromise<T>
>U : U
>IPromise : IPromise<T>
>U : U
}
declare function load(name: string): Promise<string>;
>load : (name: string) => Promise<string>
>name : string
>Promise : Promise<T>

declare function convert(s: string): IPromise<number>;
>convert : (s: string) => IPromise<number>
>s : string
>IPromise : IPromise<T>

var $$x = load("something").then(s => convert(s));
>$$x : Promise<number>
>load("something").then(s => convert(s)) : Promise<number>
>load("something").then : <U>(success?: (value: string) => Promise<U>) => Promise<U>
>load("something") : Promise<string>
>load : (name: string) => Promise<string>
>then : <U>(success?: (value: string) => Promise<U>) => Promise<U>
>s => convert(s) : (s: string) => IPromise<number>
>s : string
>convert(s) : IPromise<number>
>convert : (s: string) => IPromise<number>
>s : string