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Class `object.Exception`

The base class of all errors that are safe to catch and handle.


						
				class Exception
				
  : Throwable
				;

In principle, only thrown objects derived from this class are safe to catch inside a catch block. Thrown objects not derived from Exception represent runtime errors that should not be caught, as certain runtime guarantees may not hold, making it unsafe to continue program execution.

Constructors

Name	Description
`this` (msg, file, line, nextInChain)	Creates a new instance of Exception. The nextInChain parameter is used internally and should always be `null` when passed by user code. This constructor does not automatically throw the newly-created Exception; the `throw` statement should be used for that purpose.

Fields

Name	Type	Description
`file`	`string`	The file name of the D source code corresponding with where the error was thrown from.
`info`	`object.Throwable.TraceInfo`	The stack trace of where the error happened. This is an opaque object that can either be converted to `string`, or iterated over with `foreach` to extract the items in the stack trace (as strings).
`line`	`ulong`	The line number of the D source code corresponding with where the error was thrown from.
`msg`	`string`	A message describing the error.

Properties

Name	Type	Description
`next`[get]	`inout(Throwable)`
`next`[set]	`Throwable`	Replace next in chain with `tail`. Use `chainTogether` instead if at all possible.

Methods

Name	Description
`chainTogether` (e1, e2)	Append `e2` to chain of exceptions that starts with `e1`.
`factory` (classname)	Create instance of class specified by the fully qualified name classname. The class must either have no constructors or have a default constructor.
`message` ()	Get the message describing the error. Base behavior is to return the `Throwable.msg` field. Override to return some other error message.
`opApply` (dg)	Loop over the chain of Throwables.
`opCmp` (o)	Compare with another Object obj.
`opEquals` (o)	Test whether `this` is equal to `o`. The default implementation only compares by identity (using the `is` operator). Generally, overrides for `opEquals` should attempt to compare objects by their contents.
`refcount` ()
`toHash` ()	Compute hash function for Object.
`toString` ()	Overrides `Object.toString` and returns the error message. Internally this forwards to the `toString` overload that takes a sink delegate.
`toString` ()	The Throwable hierarchy uses a toString overload that takes a sink delegate to avoid GC allocations, which cannot be performed in certain error situations. Override this `toString` method to customize the error message.

Example

bool gotCaught;
try
{
    throw new Exception("msg");
}
catch (Exception e)
{
    gotCaught = true;
    writeln(e.msg); // "msg"
}
assert(gotCaught);

Authors

Walter Bright, Sean Kelly

License

Boost License 1.0.