• Steve Teale <steve.teale britseyeview.com> May 03 2009

Steve Teale <steve.teale britseyeview.com> writes:

Jarrett Billingsley Wrote:

 On Sun, May 3, 2009 at 4:14 PM, Denis Koroskin <2korden gmail.com> wrote:
 PHP allows function definition like this:

 void foo(Args args, string fileName = __FILE__, int line = __LINE__)
 {
  // do stuff
 }


 Hidden feature: D2 allows it too, at least with templates.
 
 void Throw(T : Throwable, string file = __FILE__, int line = __LINE__)(T ex)
 {
 	ex.file = file;
 	ex.line = line;
 	throw ex;
 }
 
 void foobar()
 {
 	Throw(new Exception("o hai"));
 }
 
 void main()
 {
 	try
 		foobar();
 	catch(RangeError e)
 		writefln("(%s: %d) %s", e.file, e.line, e.msg);
 }
 
 I did find a sort of bug when trying a slightly different
 implementation of this though - any kind of explicit instantiation of
 the Throw template causes the __FILE__ and __LINE__ to be evaluated in
 the scope of the template rather than at the call site.


Sadly this is a subterfuge that makes it impossible as far as I can see to
write code that compiles and works the same with both D1 and D2.

D1 compiles it, but reports the exception at the line where the template
function is defined.

;=(