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digitalmars.D.learn - passing all writefln arguments

reply "Saaa" <empty needmail.com> writes:
I'm trying to make my own little debug_writefln which only prints when I set 
my DEBUGG to true.

void dWritefln(...){
   if(DEBUGG==true) writefln( ? );
}

What should I place there to make this work, or should I approuch this 
wholly differently?
Mar 19 2008
parent reply Bill Baxter <dnewsgroup billbaxter.com> writes:
Saaa wrote:

 I'm trying to make my own little debug_writefln which only prints when I set 
 my DEBUGG to true.
 
 void dWritefln(...){
    if(DEBUGG==true) writefln( ? );
 }
 
 What should I place there to make this work, or should I approuch this 
 wholly differently? 
 
 



Easier if you turn it inside out.

debug(DEBUGG) {
    alias writefln dWritefln;
}
else {
    void dWritefln(...) {}
}

--bb
Mar 19 2008
parent reply "Saaa" <empty needmail.com> writes:
Thanks,

As I think that changing a variable is easier than changing the compiler 
line I went with:

const bool DEBUGG=false;

static if (DEBUGG == true) {
 alias writefln dWritefln;
}
else {
 void dWritefln(...) {}
}

Will dWritefln(..){} compile to 'nothing'?
I mean, will calling dWritefln when DEBUGG=false take no cpu tick (does the 
compiler see that it does nothing)?



 Easier if you turn it inside out.

 debug(DEBUGG) {
    alias writefln dWritefln;
 }
 else {
    void dWritefln(...) {}
 }

 --bb
Mar 20 2008
parent reply Bill Baxter <dnewsgroup billbaxter.com> writes:
Saaa wrote:

 Thanks,
 
 As I think that changing a variable is easier than changing the compiler 
 line I went with:
 
 const bool DEBUGG=false;
 
 static if (DEBUGG == true) {
  alias writefln dWritefln;
 }
 else {
  void dWritefln(...) {}
 }



I think you can set debug versions inside a file too.  That way you can 
have the best of both worlds.  Turn it on from the command line, or by 
modifying the file.

debug = DEBUGG;

debug(DEBUGG) {
  alias writefln dWritefln;
}
else {
  void dWritefln(...) {}
}

... at least that works with 'version'.  Not sure if it works with debug 
too.  (If it doesn't I'll file a bug about the inconsistency with 
'version'.)


 Will dWritefln(..){} compile to 'nothing'?
 I mean, will calling dWritefln when DEBUGG=false take no cpu tick 




 compiler see that it does nothing)?




Yes.  See thread entitled "debug()" over in digitalmars.D.
digitalmars.com digitalmars.D:66826
digitalmars.com digitalmars.D:66827

But that may only be with -inline.  Not sure what flags Jarrett used 
when he ran the test.

--bb
Mar 20 2008
parent "Saaa" <empty needmail.com> writes:
Seems to work, thanks.



 Saaa wrote:

 Thanks,

 As I think that changing a variable is easier than changing the compiler 
 line I went with:

 const bool DEBUGG=false;

 static if (DEBUGG == true) {
  alias writefln dWritefln;
 }
 else {
  void dWritefln(...) {}
 }



 I think you can set debug versions inside a file too.  That way you can 
 have the best of both worlds.  Turn it on from the command line, or by 
 modifying the file.

 debug = DEBUGG;

 debug(DEBUGG) {
  alias writefln dWritefln;
 }
 else {
  void dWritefln(...) {}
 }

 ... at least that works with 'version'.  Not sure if it works with debug 
 too.  (If it doesn't I'll file a bug about the inconsistency with 
 'version'.)


 Will dWritefln(..){} compile to 'nothing'?
 I mean, will calling dWritefln when DEBUGG=false take no cpu tick




 compiler see that it does nothing)?




 Yes.  See thread entitled "debug()" over in digitalmars.D.
 digitalmars.com digitalmars.D:66826
 digitalmars.com digitalmars.D:66827

 But that may only be with -inline.  Not sure what flags Jarrett used when 
 he ran the test.

 --bb
Mar 20 2008