std::make_exception_ptr

template <class E> exception_ptr make_exception_ptr (E e) noexcept;

Make exception_ptr

Returns an exception_ptr object that points to a copy of e.

The behavior of this function template is equivalent to:

template <class E> exception_ptr make_exception_ptr (E e) noexcept {
 try {
 throw e;
 } catch(...) {
 return current_exception();
 }
}

exception_ptr is a shared smart pointer type: The pointed exception is guaranteed to remain valid for as long as at least one exception_ptr points to it. See exception_ptr for more info.

This function throws no exceptions, but if the function is implemented as returning a pointer to a copy of the currently handled exception, it may return a pointer to a different exception if it fails to allocate storage (bad_alloc ) or if the copying process fails (it returns the thrown exception or bad_exception , if possible; or some other unspecified value, otherwise).

Parameters

e: An object or reference.

Return value

An exception_ptr object pointing to the an exception object, or some other exception if the internal process of the function would raise a new exception.

Example

// make_exception_ptr example
#include <iostream> // std::cout
#include <exception> // std::make_exception_ptr, std::rethrow_exception
#include <stdexcept> // std::logic_error
int main () {
 auto p = std::make_exception_ptr(std::logic_error("logic_error"));
 try {
 std::rethrow_exception (p);
 } catch (const std::exception& e) {
 std::cout << "exception caught: " << e.what() << '\n';
 }
 return 0;
}

Output:


exception caught: logic_error

Data races

The returned object refers to a copy of e.

Exception safety

No-throw guarantee: this function throws no exceptions. Instead, this function uses its return value to signal exceptions thrown during its internal operation.

functions

types