std::thread::id 跨进程是否唯一？
Is std::thread::id unique across processes?
根据我的经验，似乎
的结果
std::this_thread::get_id()
跨进程唯一：进程与进程之间的 ID 不同。
这个有标准保证吗？
std::thread 在支持 pthreads 的环境中在 pthreads 之上实现。所以它变得没有（便携式）保证。
来自 pthread_self 手册：
Thread IDs are guaranteed to be unique only within a process. A
thread ID may be reused after a terminated thread has been joined, or
a detached thread has terminated.
线程 ID 在不同线程中是唯一的标准受让人，它还表示终止的线程 ID 可能会被重用。它不指定流程，也不承认它们的存在，因此，它不保证跨流程的唯一性。
30.3.1.1
- An object of type thread::id provides a unique identifier for each thread of execution and a single distinct value for all thread objects
that do not represent a thread of execution (30.3.1). Each thread of
execution has an associated thread::id object that is not equal to the
thread::id object of any other thread of execution and that is not
equal to the thread::id object of any std::thread object that does not
represent threads of execution.
- thread::id shall be a trivially copyable class (Clause 9). The library may reuse the value of a thread::id of a terminated thread
that can no longer be joined.
该标准还隐藏了 thread::id 的实现，它可以是 int 或其他东西。
根据我的经验，似乎
的结果std::this_thread::get_id()
跨进程唯一：进程与进程之间的 ID 不同。
这个有标准保证吗？
std::thread 在支持 pthreads 的环境中在 pthreads 之上实现。所以它变得没有（便携式）保证。
来自 pthread_self 手册：
Thread IDs are guaranteed to be unique only within a process. A
thread ID may be reused after a terminated thread has been joined, or a detached thread has terminated.
线程 ID 在不同线程中是唯一的标准受让人，它还表示终止的线程 ID 可能会被重用。它不指定流程，也不承认它们的存在，因此，它不保证跨流程的唯一性。
30.3.1.1
- An object of type thread::id provides a unique identifier for each thread of execution and a single distinct value for all thread objects that do not represent a thread of execution (30.3.1). Each thread of execution has an associated thread::id object that is not equal to the thread::id object of any other thread of execution and that is not equal to the thread::id object of any std::thread object that does not represent threads of execution.
- thread::id shall be a trivially copyable class (Clause 9). The library may reuse the value of a thread::id of a terminated thread that can no longer be joined.
该标准还隐藏了 thread::id 的实现，它可以是 int 或其他东西。