// 2018/12/08 modified by Tsung-Wei Huang
//   - refactored the output format 
//
// 2018/12/07 modified by Tsung-Wei Huang
//   - refactored the output format
//
// 2018/12/06 modified by Tsung-Wei Huang
//   - added nested insertions test
//
// 2018/12/04 modified by Tsung-Wei Huang
//   - replace privatized threadpool with work stealing threadpool
//   
// 2018/10/04 modified by Tsung-Wei Huang
//   - removed binary_tree
//   - removed modulo_insertions
//   - adopted to the new threadpool implementation
//
// 2018/09/19 modified by Tsung-Wei Huang
//   - added binary_tree benchmark
//   - added modulo_insertions benchmark
//   - refactored benchmark calls
//
// 2018/08/31 contributed by Guannan
//
// Examples to test different threadpool implementations:
//   - SimpleThreadpool
//   - ProactiveThreadpool
//   - SpeculativeThreadpool
//   - PrivatizedThreadpool

#include 
#include 
#include 
#include 
#include 
#include 
#include 

constexpr int WIDTH = 12;

using Closure = std::function;

// Procedure: benchmark
#define BENCHMARK(TITLE, F)                                                     \
std::cout                                                                       \