std::atexit - cppreference.com (original) (raw)
Registers the function pointed to by func to be called on normal program termination (via std::exit() or returning from the main function)
| The functions will be called during the destruction of the static objects, in reverse order: if A was registered before B, then the call to B is made before the call to A. Same applies to the ordering between static object constructors and the calls to atexit: see std::exit. | (until C++11) |
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| The functions may be called concurrently with the destruction of the objects with static storage duration and with each other, maintaining the guarantee that if registration of A was sequenced-before the registration of B, then the call to B is sequenced-before the call to A, same applies to the sequencing between static object constructors and calls to atexit: see std::exit. | (since C++11) |
The same function may be registered more than once.
If a function exits via an exception, std::terminate is called.
atexit is thread-safe: calling the function from several threads does not induce a data race.
The implementation is guaranteed to support the registration of at least 32 functions. The exact limit is implementation-defined.
[edit] Parameters
| func | - | pointer to a function to be called on normal program termination |
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[edit] Return value
0 if the registration succeeds, nonzero value otherwise.
[edit] Notes
The two overloads are distinct because the types of the parameter func are distinct (language linkage is part of its type).
[edit] Example
#include #include void atexit_handler_1() { std::cout << "At exit #1\n"; } void atexit_handler_2() { std::cout << "At exit #2\n"; } int main() { const int result_1 = std::atexit(atexit_handler_1); const int result_2 = std::atexit(atexit_handler_2); if (result_1 || result_2) { std::cerr << "Registration failed!\n"; return EXIT_FAILURE; } std::cout << "Returning from main...\n"; return EXIT_SUCCESS; }
Output:
Returning from main... At exit #2 At exit #1