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• When the exception handling mechanism, after completing the initialization of the exception object but before activation of a handler for the exception, calls a function that exits via an exception. ([except.throw], paragraph 7)
  
• When a throw-expression with no operand attempts to rethrow an exception and no exception is being handled. ([except.throw], paragraph 9)
• When the exception handling mechanism cannot find a handler for a thrown exception. ([except.handle], paragraph 9)
  • See ERR31-CPP. Handle all exceptions for more information.
• When the search for a handler encounters the outermost block of a function with a noexcept-specification that does not allow the exception. ([except.spec], paragraph 9)
  • See ERR37-CPP. Honor exception specifications for more information.
• When the destruction of an object during stack unwinding terminates by throwing an exception. ([except.ctor], paragraph 3)
  • See DCL40DCL58-CPP. Destructors and deallocation functions must be declared noexcept for more information.
• When initialization of a non-local variable with static or thread storage duration exits via an exception. ([basic.start.init], paragraph 6)
  
  • See ERR41-CPP. Constructors of objects with static or thread storage duration must not throw exceptions for more information.
• When destruction of an object with static or thread storage duration exits via an exception. ([basic.start.term], paragraph 1)
  • See DCL40DCL58-CPP. Destructors and deallocation functions must be declared noexcept
• When execution of a function registered with std::atexit() or std::at_quick_exit() exits via an exception. ([support.start.term], paragraphs 8 and 12)
• When the implementation’s default unexpected exception handler is called. ([except.unexpected], paragraph 2) Note that std::unexpected() is currently deprecated.
• When std::unexpected() throws an exception which is not allowed by the previously violated dynamic-exception-specification, and std::bad_exception() is not included in that dynamic-exception-specification. ([except.unexpected], paragraph 3)
  
• When the function std::nested_exception::rethrow_nested() is called for an object that has captured no exception. ([except.nested], paragraph 4)
  
• When execution of the initial function of a thread exits via an exception. ([thread.thread.constr], paragraph 5)
  • See ERR31-CPP. Handle all exceptions for more information.
• When the destructor is invoked on an object of type std::thread that refers to a joinable thread. ([thread.thread.destr], paragraph 1)
• When the copy assignment operator is invoked on an object of type std::thread that refers to a joinable thread. ([thread.thread.assign], paragraph 1)
  
• When calling condition_variable::wait(), condition_variable::wait_until(), or condition_variable::wait_for() results in a failure to meet the post-condition: lock.owns_lock() == true or lock.mutex() is not locked by the calling thread. ([thread.condition.condvar], paragraphs 11, 16, 21, 28, 33, and 40)
• When calling condition_variable_any::wait(), condition_variable_any::wait_until(), or condition_variable_any::wait_for() results in a failure to meet the post-condition: lock is not locked by the calling thread. ([thread.condition.condvarany], paragraphs 11, 16, and 22)

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In this noncompliant code example, the thread entrypoint function thread_start() does not catch exceptions thrown by throwing_func(). If the initial thread function exits due to an exception being thrown, std::terminate() is called.

#include <thread>

void throwing_func() noexcept(false);
 
void thread_start(void) {
  throwing_func();
}
 
void f() {
  std::thread t(thread_start);
  t.join();
}

Compliant Solution

In this compliant solution, the thread_start() handles all exceptions and does not rethrow, allowing the thread to terminate normally:

#include <thread>

void throwing_func() noexcept(false);

void thread_start(void) {
  try {
    throwing_func();
  } catch (...) {
    // Handle error
  }
}

void f() {
  std::thread t(thread_start);
  t.join();
}

Noncompliant Code Example

In this noncompliant code example, the call to f(), which was registered as an exit handler with std::at_exit(), may result in a call to std::terminate() because throwing_func() may throw an exception:

#include <cstdlib>
 
void throwing_func() noexcept(false);
 
void f() {
  throwing_func();
}
 
int main() {
  if (0 != std::atexit(f)) {
    // Handle error
  }
  // ...
}

Compliant Solution

In this compliant solution, f() handles all exceptions thrown by throwing_func(), and does not rethrow:

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Related Guidelines

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