std::at_quick_exit
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(C++23)
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) 
int at_quick_exit( /*c-atexit-handler*/* func ) noexcept;
extern "C++" using /*atexit-handler*/ = void();
extern "C" using /*c-atexit-handler*/ = void();
 (2) 
 (exposition only*) 
extern "C" using /*c-atexit-handler*/ = void();
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.
Contents
[edit] Parameters
 func
 -
 pointer to a function to be called on quick program termination
[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
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
[edit] See also
C documentation  for at_quick_exit