Exception handling

Collaboration diagram for Exception handling:

Files
file	exceptions.hh
	A few common exception classes.

Classes
class	Dune::Exception
	Base class for Dune-Exceptions. More...
struct	Dune::ExceptionHook
	Base class to add a hook to the Dune::Exception. More...
class	Dune::ExceptionStream< E >
	Class for extending a Dune::Exception with a stream interface. More...
class	Dune::IOError
	Default exception class for I/O errors. More...
class	Dune::MathError
	Default exception class for mathematical errors. More...
class	Dune::RangeError
	Default exception class for range errors. More...
class	Dune::NotImplemented
	Default exception for dummy implementations. More...
class	Dune::SystemError
	Default exception class for OS errors. More...
class	Dune::OutOfMemoryError
	Default exception if memory allocation fails. More...
class	Dune::InvalidStateException
	Default exception if a function was called while the object is not in a valid state for that function. More...
class	Dune::ParallelError
	Default exception if an error in the parallel communication of the program occurred. More...

Macros
#define	DUNE_THROW(E, ...)   throw Dune::ExceptionStream(E()) << THROWSPEC(E) __VA_OPT__(<<) __VA_ARGS__

Functions
	Dune::Exception::Exception ()
void	Dune::Exception::message (const std::string &msg)
	store string in internal message buffer More...
const char *	Dune::Exception::what () const noexcept override
	output internal message buffer More...
static void	Dune::Exception::registerHook (ExceptionHook *hook)
	add a functor which is called before a Dune::Exception is emitted (see Dune::ExceptionHook) More...
static void	Dune::Exception::clearHook ()
	remove all hooks More...
virtual	Dune::ExceptionHook::~ExceptionHook ()
virtual void	Dune::ExceptionHook::operator() ()=0
std::ostream &	Dune::operator<< (std::ostream &stream, const Exception &e)
	Dune::ExceptionStream< E >::ExceptionStream (const E &other)
	Dune::ExceptionStream< E >::ExceptionStream (E &&other)
template<class T >
	Dune::ExceptionStream< E >::requires (requires(std::ostringstream &oss, T t) { oss<< t;} and not std::is_integral_v< T >) friend ExceptionStream &operator<<(ExceptionStream &es
	Stream operator for l-value ExceptionStream and lvalue-reference. More...
es	Dune::ExceptionStream< E >::message (es.sstream_.str())
template<class T >
	Dune::ExceptionStream< E >::requires (requires(std::ostringstream &oss, T t) { oss<< t;} and not std::is_integral_v< T >) friend ExceptionStream operator<<(ExceptionStream &&es
	Stream operator for r-value ExceptionStream and lvalue-reference. More...
return	Dune::ExceptionStream< E >::std::move (es)

Variables
const T &	Dune::ExceptionStream< E >::t
return	Dune::ExceptionStream< E >::es

Friends
template<class T >
requires std::is_integral_v< T > friend ExceptionStream &	Dune::ExceptionStream< E >::operator<< (ExceptionStream &es, T t)
	Stream operator for l-value ExceptionStream and integral values. More...
template<class T >
requires std::is_integral_v< T > friend ExceptionStream	Dune::ExceptionStream< E >::operator<< (ExceptionStream &&es, T t)
	Stream operator for r-value ExceptionStream and integral values. More...
ExceptionStream &	Dune::ExceptionStream< E >::operator<< (ExceptionStream &es, std::ostream &(*t)(std::ostream &))
	Stream operator for l-value ExceptionStream and io manipulator. More...
ExceptionStream	Dune::ExceptionStream< E >::operator<< (ExceptionStream &&es, std::ostream &(*t)(std::ostream &))
	Stream operator for r-value ExceptionStream and io manipulator. More...

Detailed Description

The Dune-exceptions are designed to allow a simple derivation of subclasses and to accept a text written in the '<<' syntax.

Example of usage:

#include <dune/common/exceptions.hh>

...

class FileNotFoundError : public Dune::IOError {};

...

void fileopen (std::string name) {
std::ifstream file;

file.open(name.c_str());

if (file == 0)
 DUNE_THROW(FileNotFoundError, "File " << name << " not found!");

...

file.close();
}

...

int main () {
try {
 ...
} catch (Dune::IOError &e) {
 std::cerr << "I/O error: " << e << std::endl;
 return 1;
} catch (Dune::Exception &e) {
 std::cerr << "Generic Dune error: " << e << std::endl;
 return 2;
}
}

See also

exceptions.hh for detailed info

Macro Definition Documentation

DUNE_THROW

#define DUNE_THROW	(		E,
			...
	)		throw Dune::ExceptionStream(E()) << THROWSPEC(E) __VA_OPT__(<<) __VA_ARGS__

Macro to throw an exception

#include <dune/common/exceptions.hh>

Parameters

E	exception class derived from Dune::Exception
m	reason for this exception in ostream-notation

Example:

if (filehandle == 0)
 DUNE_THROW(FileError, "Could not open " << filename << " for reading!");

DUNE_THROW automatically adds information about the exception thrown to the text.

Note

you can add a hook to be called before a Dune::Exception is emitted, e.g. to add additional information to the exception, or to invoke a debugger during parallel debugging. (see Dune::ExceptionHook)

Function Documentation

clearHook()

void Dune::Exception::clearHook ( )

static

remove all hooks

Exception()

Dune::Exception::Exception

(

)

ExceptionStream() [1/2]

template<class E >

Dune::ExceptionStream< E >::ExceptionStream ( const E &  other )

inline

ExceptionStream() [2/2]

template<class E >

Dune::ExceptionStream< E >::ExceptionStream ( E &&  other )

inline

message() [1/2]

void Dune::Exception::message

(

const std::string &

msg

)

store string in internal message buffer

message() [2/2]

template<class E >

es Dune::ExceptionStream< E >::message

(

es.sstream_.

str()

)

operator()()

virtual void Dune::ExceptionHook::operator() ( )

pure virtual

operator<<()

std::ostream& Dune::operator<< ( std::ostream &  stream, const Exception &  e  )

inline

registerHook()

void Dune::Exception::registerHook ( ExceptionHook *  hook )

static

add a functor which is called before a Dune::Exception is emitted (see Dune::ExceptionHook)

See also

Dune::ExceptionHook

requires() [1/2]

template<class E >

template<class T >

Dune::ExceptionStream< E >::requires

(

requires(std::ostringstream &oss, T t) { oss<< t;} and not std::is_integral_v< T >

)

&

Stream operator for l-value ExceptionStream and lvalue-reference.

requires() [2/2]

template<class E >

template<class T >

Dune::ExceptionStream< E >::requires

(

requires(std::ostringstream &oss, T t) { oss<< t;} and not std::is_integral_v< T >

)

&&

Stream operator for r-value ExceptionStream and lvalue-reference.

std::move()

template<class E >

return Dune::ExceptionStream< E >::std::move

(

es

)

what()

const char * Dune::Exception::what ( ) const

overridenoexcept

output internal message buffer

~ExceptionHook()

virtual Dune::ExceptionHook::~ExceptionHook ( )

inlinevirtual

Variable Documentation

es

template<class E >

return Dune::ExceptionStream< E >::es

t

template<class E >

const T & Dune::ExceptionStream< E >::t

Initial value:

{
      es.sstream_ << t

Friends

operator<< [1/4]

template<class E >

template<class T >

requires std::is_integral_v<T> friend ExceptionStream& operator<< ( ExceptionStream< E > &  es, T  t  )

friend

Stream operator for l-value ExceptionStream and integral values.

This is needed to support passing a static const members. The other overload leads to ODR use which requires that there is a namespace scope definition of the variable (which does often not exist).

operator<< [2/4]

template<class E >

template<class T >

requires std::is_integral_v<T> friend ExceptionStream operator<< ( ExceptionStream< E > &&  es, T  t  )

friend

Stream operator for r-value ExceptionStream and integral values.

operator<< [3/4]

template<class E >

ExceptionStream& operator<< ( ExceptionStream< E > &  es, std::ostream &(*)(std::ostream &)  t  )

friend

Stream operator for l-value ExceptionStream and io manipulator.

operator<< [4/4]

template<class E >

ExceptionStream operator<< ( ExceptionStream< E > &&  es, std::ostream &(*)(std::ostream &)  t  )

friend

Stream operator for r-value ExceptionStream and io manipulator.