Map ptr (#5)

* add map conversion

* map to pointers

* lint

slice/map.go

@@ -29,3 +29,14 @@ func Map[T any, R any](in []T, fn MapFn[T, R]) []R {
 	}
 	return rtn
 }
+
+// MapToPtr transforms a slice into a slice of pointers
+// to the same elements.
+func MapToPtr[T any](in []T) []*T {
+	rtn := make([]*T, len(in))
+	for i, e := range in {
+		e := e
+		rtn[i] = &e
+	}
+	return rtn
+}

slice/map_test.go

@@ -71,3 +71,23 @@ func TestMap(t *testing.T) {
 		t.Fatalf("mismatch (-want, +got):\n%s", diff)
 	}
 }
+
+func TestMapPtr(t *testing.T) {
+	t.Parallel()
+	in := []Person{
+		{
+			Name: "Alice",
+			Age:  30,
+		},
+		{
+			Name: "Bob",
+			Age:  31,
+		},
+	}
+
+	got := slice.MapToPtr(in)
+	want := []*Person{&in[0], &in[1]}
+	if diff := cmp.Diff(want, got); diff != "" {
+		t.Fatalf("mismatch (-want, +got):\n%s", diff)
+	}
+}