◐ Shell clean mode source ↗

std::throw_with_nested – cppreference.com

Aus cppreference.com

<metanoindex/>

<tbody> </tbody>

definiert in Header `<exception>`

`template< class T > [[noreturn]] void throw_with_nested( T&& t );`		(seit C++11)

Löst eine Ausnahme von unspezifizierten Typ, der sowohl aus std::nested_exception und von std::remove_reference<T>::type abgeleitet ist, und hergestellt aus std::forward<T>(t). Der Standardkonstruktor der nested_exception Muttergesellschaft nennt std::current_exception, Einfangen aktuell behandelte Ausnahme-Objekt, wenn überhaupt, in std::exception_ptr .

Original:

Throws an exception of unspecified type that is derived from both std::nested_exception and from std::remove_reference<T>::type, and constructed from std::forward<T>(t). The default constructor of the nested_exception parent calls std::current_exception, capturing the currently handled exception object, if any, in std::exception_ptr.

The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

Wenn std::remove_reference<T>::type ist bereits aus std::nested_exception abgeleitet, einfach wirft std::forward<T>(t) .

Original:

If std::remove_reference<T>::type is already derived from std::nested_exception, simply throws std::forward<T>(t).

The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

Erfordert, dass std::remove_reference<T>::type CopyConstructible ist

Original:

The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

Parameter

t

-

das Exception-Objekt zu werfen

Original:

the exception object to throw

The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

Rückgabewert

(None)

Original:

(none)

The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

Beispiel

Demonstriert, Bau und Rekursion durch eine verschachtelte Exception-Objekt

Original:

Demonstrates construction and recursion through a nested exception object

The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

#include <iostream>
#include <stdexcept>
#include <exception>
#include <string>
#include <fstream>

// prints the explanatory string of an exception. If the exception is nested,
// recurses to print the explanatory of the exception it holds
void print_exception(const std::exception& e, int level =  0)
{
    std::cerr << std::string(level, ' ') << "exception: " << e.what() << '\n';
    try {
        std::rethrow_if_nested(e);
    } catch(const std::exception& e) {
        print_exception(e, level+1);
    } catch(...) {}
}

// sample function that catches an exception and wraps it in a nested exception
void open_file(const std::string& s)
{
    try {
        std::ifstream file(s);
        file.exceptions(std::ios_base::failbit);
    } catch(...) {
        std::throw_with_nested( std::runtime_error("Couldn't open " + s) );
    }
}

// sample function that catches an exception and wraps it in a nested exception
void run()
{
    try {
        open_file("nonexistent.file");
    } catch(...) {
        std::throw_with_nested( std::runtime_error("run() failed") );
    }
}

// runs the sample function above and prints the caught exception
int main()
{
    try {
        run();
    } catch(const std::exception& e) {
        print_exception(e);
    }
}

Output:

exception: run() failed
 exception: Couldn't open nonexistent.file
  exception: basic_ios::clear

Siehe auch


	a mixin Art zu erfassen und zu speichern aktuellen Ausnahmen Original: a mixin type to capture and store current exceptions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (Klasse) [edit]

	wirft die Ausnahme von einer std::nested_exception Original: throws the exception from a std::nested_exception The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (Funktions-Template) [edit]