Threads in a vector can't be joined

I want to store a collection of threads in a vector, and join them all before exiting my program. I receive the following error when trying to join the first thread no matter how many I place in the collection:

system_error: thread::join failed: No such process

Here is some simple code that demonstrates my issue:

#include <thread>
#include <iostream>
#include <vector>
#include <functional>

using std::cout;
using std::endl;
using std::vector;
using std::thread;
using std::mem_fn;

int main()
{
  vector<thread> threads(1);
  threads.push_back(thread([]{ cout << "Hello" << endl; }));
  for_each(threads.begin(), threads.end(), mem_fn(&thread::join));

  // also tried --> for(thread &t : threads) t.join()
}

And I'm building it using the following (tried clang++ 4.2.1 and g++ 5.3.1):

g++ -o src/thread_test.o -c -std=c++14 src/thread_test.cpp
g++ -o thread_test src/thread_test.o -lpthread

I see lots of examples doing just this around the internet. Did something change in the contract of <thread> or <vector> that's rendered these examples defunct?