std::at_quick_exit

 

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Program support utilities

Program termination
abort exit quick_exit (C++11) _Exit (C++11)	atexit at_quick_exit (C++11) EXIT_SUCCESSEXIT_FAILURE
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unreachable (C++23)
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system	getenv
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SIGABRTSIGFPESIGILL	SIGINTSIGSEGVSIGTERM
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setjmp	longjmp
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jmp_buf

 

Defined in header <cstdlib>
int at_quick_exit( /*atexit-handler*/* func ) noexcept; int at_quick_exit( /*c-atexit-handler*/* func ) noexcept;	(1)	(since C++11)
extern "C++" using /*atexit-handler*/ = void(); extern "C" using /*c-atexit-handler*/ = void();	(2)	(exposition only*)

Registers the function pointed to by func to be called on quick program termination (via std::quick_exit).

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.

The registered functions will not be called on normal program termination. If a function need to be called in that case, std::atexit must be used.

Parameters

func

-

pointer to a function to be called on quick program termination

Return value

​0​ if the registration succeeds, nonzero value otherwise.

Notes

The two overloads are distinct because the types of the parameter func are distinct (language linkage is part of its type).

Example

Run this code

#include <cstdlib>
#include <iostream>
 
void f1()
{
    std::cout << "pushed first" << std::endl; // flush is intentional
}
 
extern "C" void f2()
{
    std::cout << "pushed second\n";
}
 
int main()
{
    auto f3 = []
    {
        std::cout << "pushed third\n";
    };
 
    std::at_quick_exit(f1);
    std::at_quick_exit(f2);
    std::at_quick_exit(f3);
    std::quick_exit(0);
}

Output:

pushed third
pushed second
pushed first

See also

abort	causes abnormal program termination (without cleaning up) (function)
exit	causes normal program termination with cleaning up (function)
atexit	registers a function to be called on std::exit() invocation (function)
quick_exit (C++11)	causes quick program termination without completely cleaning up (function)
C documentation for at_quick_exit