Name the worker threads of boost’s threadpool

thread_name.h

#include <cassert>
#include <condition_variable>
#include <cstddef>
#include <mutex>
#include <string>

#include "boost/threadpool.hpp"

void NameThisThread(const std::string& name);

template <
    typename Task,
    template <typename> class SchedulingPolicy,
    template <typename> class SizePolicy,
    template <typename> class SizePolicyController,
    template <typename> class ShutdownPolicy>
inline void NameThreadpoolWorkers(
    const std::string& name,
    boost::threadpool::thread_pool<
        Task, SchedulingPolicy, SizePolicy,
        SizePolicyController, ShutdownPolicy> *pool) {
  assert(pool);
  pool->wait();
  std::mutex mutex;
  std::condition_variable condition;
  bool predicate = false;
  std::unique_lock<std::mutex> lock(mutex);
  for (std::size_t i = 0; i < pool->size(); ++i) {
    pool->schedule([&name, &mutex, &condition, &predicate]() {
      std::unique_lock<std::mutex> lock(mutex);
      while (!predicate) {
        condition.wait(lock);
      }
      NameThisThread(name);
    });
  }
  predicate = true;
  condition.notify_all();
  lock.unlock();
  pool->wait();
}

thread_name.mm

#include "thread_name.h"

#include <string>

#import <Cocoa/Cocoa.h>

void NameThisThread(const std::string& name) {
  NSString *string;
  if (string.empty()) {
    string = [NSString string];
  } else {
    string = [NSString stringWithUTF8String:string.c_str()];
  }
  [[NSThread currentThread] setName:string];
}