Figure 1: Defines three classes for representing Promise resolved, rejected, and pending state. Those classes are Resolved State, Rejected State, and Pending State

Figure 2: Shows the design for a settlement object which resolves or rejects a Promise

Figure 3: Illustrates the change in cyclomatic complexity across Promise designs

Figure 4: Shows run-times for each library

Listing 1: A simple example illustrating the structure and behavior of Promise code in JavaScript

Listing 2: The Promise-cpp version of the JavaScript code sample where two separate Defers are created. The first starts a then() chain and the second begins another using the same resolved value

Listing 3: The PoolQueue version of the JavaScript code sample where two then () chains are began using the same Promise. Note the call to settle a Promise at the bottom

Listing 4: The STL version of the JavaScript code sample where Promises are managed using a combition of STL futures Promises and threads

Listing 5: The HPX version of the JavaScript code sample where Futures are used instead of Promises

Listing 6: The STLab version of the JavaScript code sample where Futures are used instead of Promises

Listing 7: The Promise++ version of the JavaScript code sample

Listing 8: Handle many Promises in a C++ Map and reference the results with the same keys