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Defined in header <exception> | ||
[[noreturn]]void rethrow_exception(std::exception_ptr p); | (since C++11) (constexpr since C++26) | |
Throws the previously captured exception object referred-to by the exception pointerp, or a copy of that object.
It is unspecified whether a copy is made. If a copy is made, the storage for it is allocated in an unspecified way.
The behavior is undefined ifp is null.
Contents |
| p | - | non-nullstd::exception_ptr |
The exception object referred-to byp if no copy is made.
Otherwise, a copy of such exception object if the implementation successfully copied the exception object.
Otherwise,std::bad_alloc or the exception thrown when copying the exception object, if allocation or copying fails, respectively.
BeforeP1675R2,rethrow_exception was not allowed to copy the exception object, which is unimplementable on some platforms where exception objects are allocated on the stack.
| Feature-test macro | Value | Std | Feature |
|---|---|---|---|
__cpp_lib_constexpr_exceptions | 202411L | (C++26) | constexpr for exception types |
#include <exception>#include <iostream>#include <stdexcept>#include <string> void handle_eptr(std::exception_ptr eptr)// passing by value is OK{try{if(eptr) std::rethrow_exception(eptr);}catch(conststd::exception& e){std::cout<<"Caught exception: '"<< e.what()<<"'\n";}} int main(){std::exception_ptr eptr; try{[[maybe_unused]]char ch=std::string().at(1);// this generates a std::out_of_range}catch(...){ eptr=std::current_exception();// capture} handle_eptr(eptr); }// destructor for std::out_of_range called here, when the eptr is destructed
Possible output:
Caught exception: 'basic_string::at: __n (which is 1) >= this->size() (which is 0)'
(C++11) | shared pointer type for handling exception objects (typedef)[edit] |
(C++11) | captures the current exception in astd::exception_ptr (function)[edit] |
