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Class object.Error

The base class of all unrecoverable runtime errors.

class Error
  : Throwable ;

This represents the category of Throwable objects that are not safe to catch and handle. In principle, one should not catch Error objects, as they represent unrecoverable runtime errors. Certain runtime guarantees may fail to hold when these errors are thrown, making it unsafe to continue execution after catching them.


this (msg, nextInChain) Creates a new instance of Error. 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 Error; the throw statement should be used for that purpose.


bypassedException ThrowableThe first Exception which was bypassed when this Error was thrown, or null if no Exceptions were pending.
file stringThe file name of the D source code corresponding with where the error was thrown from.
info object.Throwable.TraceInfoThe 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 ulongThe line number of the D source code corresponding with where the error was thrown from.
msg stringA message describing the error.


next[get] inout(Throwable)
next[set] ThrowableReplace next in chain with tail. Use chainTogether instead if at all possible.


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.


bool gotCaught;
    throw new Error("msg");
catch (Error e)
    gotCaught = true;
    writeln(e.msg); // "msg"


Walter Bright, Sean Kelly


Boost License 1.0.