tmp/tmphvhh0k60/{from.md → to.md}
RENAMED
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| 1 |
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#### Class template `scoped_lock` <a id="thread.lock.scoped">[[thread.lock.scoped]]</a>
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``` cpp
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namespace std {
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template <class... MutexTypes>
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class scoped_lock {
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public:
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using mutex_type = Mutex; // If MutexTypes... consists of the single type Mutex
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explicit scoped_lock(MutexTypes&... m);
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explicit scoped_lock(MutexTypes&... m, adopt_lock_t);
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~scoped_lock();
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scoped_lock(const scoped_lock&) = delete;
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scoped_lock& operator=(const scoped_lock&) = delete;
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private:
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tuple<MutexTypes&...> pm; // exposition only
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};
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template<class... MutexTypes>
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scoped_lock(scoped_lock<MutexTypes...>) -> scoped_lock<MutexTypes...>;
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}
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```
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An object of type `scoped_lock` controls the ownership of lockable
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objects within a scope. A `scoped_lock` object maintains ownership of
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lockable objects throughout the `scoped_lock` object’s lifetime (
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[[basic.life]]). The behavior of a program is undefined if the lockable
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objects referenced by `pm` do not exist for the entire lifetime of the
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`scoped_lock` object. When `sizeof...(MutexTypes)` is `1`, the supplied
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`Mutex` type shall meet the `BasicLockable` requirements (
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[[thread.req.lockable.basic]]). Otherwise, each of the mutex types shall
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meet the `Lockable` requirements ([[thread.req.lockable.req]]).
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``` cpp
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explicit scoped_lock(MutexTypes&... m);
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```
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*Requires:* If a `MutexTypes` type is not a recursive mutex, the calling
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thread does not own the corresponding mutex element of `m`.
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*Effects:* Initializes `pm` with `tie(m...)`. Then if
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`sizeof...(MutexTypes)` is `0`, no effects. Otherwise if
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`sizeof...(MutexTypes)` is `1`, then `m.lock()`. Otherwise,
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`lock(m...)`.
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``` cpp
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explicit scoped_lock(MutexTypes&... m, adopt_lock_t);
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```
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*Requires:* The calling thread owns all the mutexes in `m`.
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*Effects:* Initializes `pm` with `tie(m...)`.
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*Throws:* Nothing.
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``` cpp
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~scoped_lock();
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```
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*Effects:* For all `i` in \[`0`, `sizeof...(MutexTypes)`),
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`get<i>(pm).unlock()`.
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