=== tests/cases/compiler/contextualSignatureInstantiation3.ts ===
function map<T, U>(items: T[], f: (x: T) => U): U[]{
>map : Symbol(map, Decl(contextualSignatureInstantiation3.ts, 0, 0))
>T : Symbol(T, Decl(contextualSignatureInstantiation3.ts, 0, 13))
>U : Symbol(U, Decl(contextualSignatureInstantiation3.ts, 0, 15))
>items : Symbol(items, Decl(contextualSignatureInstantiation3.ts, 0, 19))
>T : Symbol(T, Decl(contextualSignatureInstantiation3.ts, 0, 13))
>f : Symbol(f, Decl(contextualSignatureInstantiation3.ts, 0, 30))
>x : Symbol(x, Decl(contextualSignatureInstantiation3.ts, 0, 35))
>T : Symbol(T, Decl(contextualSignatureInstantiation3.ts, 0, 13))
>U : Symbol(U, Decl(contextualSignatureInstantiation3.ts, 0, 15))
>U : Symbol(U, Decl(contextualSignatureInstantiation3.ts, 0, 15))

    return items.map(f);
>items.map : Symbol(Array.map, Decl(lib.d.ts, 1115, 92))
>items : Symbol(items, Decl(contextualSignatureInstantiation3.ts, 0, 19))
>map : Symbol(Array.map, Decl(lib.d.ts, 1115, 92))
>f : Symbol(f, Decl(contextualSignatureInstantiation3.ts, 0, 30))
}

function identity<T>(x: T) {
>identity : Symbol(identity, Decl(contextualSignatureInstantiation3.ts, 2, 1))
>T : Symbol(T, Decl(contextualSignatureInstantiation3.ts, 4, 18))
>x : Symbol(x, Decl(contextualSignatureInstantiation3.ts, 4, 21))
>T : Symbol(T, Decl(contextualSignatureInstantiation3.ts, 4, 18))

    return x;
>x : Symbol(x, Decl(contextualSignatureInstantiation3.ts, 4, 21))
}

function singleton<T>(x: T) {
>singleton : Symbol(singleton, Decl(contextualSignatureInstantiation3.ts, 6, 1))
>T : Symbol(T, Decl(contextualSignatureInstantiation3.ts, 8, 19))
>x : Symbol(x, Decl(contextualSignatureInstantiation3.ts, 8, 22))
>T : Symbol(T, Decl(contextualSignatureInstantiation3.ts, 8, 19))

    return [x];
>x : Symbol(x, Decl(contextualSignatureInstantiation3.ts, 8, 22))
}

var xs = [1, 2, 3];
>xs : Symbol(xs, Decl(contextualSignatureInstantiation3.ts, 12, 3))

// Have compiler check that we get the correct types
var v1: number[];
>v1 : Symbol(v1, Decl(contextualSignatureInstantiation3.ts, 15, 3), Decl(contextualSignatureInstantiation3.ts, 16, 3), Decl(contextualSignatureInstantiation3.ts, 17, 3))

var v1 = xs.map(identity);      // Error if not number[]
>v1 : Symbol(v1, Decl(contextualSignatureInstantiation3.ts, 15, 3), Decl(contextualSignatureInstantiation3.ts, 16, 3), Decl(contextualSignatureInstantiation3.ts, 17, 3))
>xs.map : Symbol(Array.map, Decl(lib.d.ts, 1115, 92))
>xs : Symbol(xs, Decl(contextualSignatureInstantiation3.ts, 12, 3))
>map : Symbol(Array.map, Decl(lib.d.ts, 1115, 92))
>identity : Symbol(identity, Decl(contextualSignatureInstantiation3.ts, 2, 1))

var v1 = map(xs, identity);     // Error if not number[]
>v1 : Symbol(v1, Decl(contextualSignatureInstantiation3.ts, 15, 3), Decl(contextualSignatureInstantiation3.ts, 16, 3), Decl(contextualSignatureInstantiation3.ts, 17, 3))
>map : Symbol(map, Decl(contextualSignatureInstantiation3.ts, 0, 0))
>xs : Symbol(xs, Decl(contextualSignatureInstantiation3.ts, 12, 3))
>identity : Symbol(identity, Decl(contextualSignatureInstantiation3.ts, 2, 1))

var v2: number[][];         
>v2 : Symbol(v2, Decl(contextualSignatureInstantiation3.ts, 19, 3), Decl(contextualSignatureInstantiation3.ts, 20, 3), Decl(contextualSignatureInstantiation3.ts, 21, 3))

var v2 = xs.map(singleton);     // Error if not number[][]
>v2 : Symbol(v2, Decl(contextualSignatureInstantiation3.ts, 19, 3), Decl(contextualSignatureInstantiation3.ts, 20, 3), Decl(contextualSignatureInstantiation3.ts, 21, 3))
>xs.map : Symbol(Array.map, Decl(lib.d.ts, 1115, 92))
>xs : Symbol(xs, Decl(contextualSignatureInstantiation3.ts, 12, 3))
>map : Symbol(Array.map, Decl(lib.d.ts, 1115, 92))
>singleton : Symbol(singleton, Decl(contextualSignatureInstantiation3.ts, 6, 1))

var v2 = map(xs, singleton);    // Error if not number[][]
>v2 : Symbol(v2, Decl(contextualSignatureInstantiation3.ts, 19, 3), Decl(contextualSignatureInstantiation3.ts, 20, 3), Decl(contextualSignatureInstantiation3.ts, 21, 3))
>map : Symbol(map, Decl(contextualSignatureInstantiation3.ts, 0, 0))
>xs : Symbol(xs, Decl(contextualSignatureInstantiation3.ts, 12, 3))
>singleton : Symbol(singleton, Decl(contextualSignatureInstantiation3.ts, 6, 1))