• Qian Xu <quian.xu stud.tu-ilmenau.de> Apr 04 2009
• grauzone <none example.net> Apr 04 2009
• Qian Xu <quian.xu stud.tu-ilmenau.de> Apr 06 2009
• grauzone <none example.net> Apr 06 2009
• Qian Xu <quian.xu stud.tu-ilmenau.de> Apr 06 2009
• Frank Benoit <keinfarbton googlemail.com> Apr 04 2009

Qian Xu <quian.xu stud.tu-ilmenau.de> writes:

Hi All,

tango.text.convert.Format provides a nice function to convert anything 
to string.

It works perfect except the argument is a pointer type.
It will print the address of a pointer instead of its value

For instance: --------------------------------
int* i = new int;
*i = 10;
Format.convert("{}", i); // <- the address of the pointer
----------------------------------------------

How to let it print the value instead of the address?
Because I wanna write a dump function to dump the value of any data type 
(also void, null)




-- 
Xu, Qian (stanleyxu)
  http://stanleyxu2005.blogspot.com

grauzone <none example.net> writes:

Qian Xu wrote:
 Hi All,
 
 tango.text.convert.Format provides a nice function to convert anything 
 to string.
 
 It works perfect except the argument is a pointer type.
 It will print the address of a pointer instead of its value
 
 For instance: --------------------------------
 int* i = new int;
 *i = 10;
 Format.convert("{}", i); // <- the address of the pointer
 ----------------------------------------------
 
 How to let it print the value instead of the address?
 Because I wanna write a dump function to dump the value of any data type 
 (also void, null)


Check if the variable is a pointer, and if yes, dereference it:

alias typeof(i) T;
static if (is(T T2 : T2*)) {
	T2 i2 = *i;
	Format.convert("{}", i2);
} else {
	Format.convert("{}", i);
}

Qian Xu <quian.xu stud.tu-ilmenau.de> writes:

grauzone wrote:

 
 Check if the variable is a pointer, and if yes, dereference it:
 
 alias typeof(i) T;
 static if (is(T T2 : T2*)) {
 T2 i2 = *i;
 Format.convert("{}", i2);
 } else {
 Format.convert("{}", i);
 }


Hi again,

I cannot compile this code 

grauzone <none example.net> writes:

Qian Xu wrote:
 grauzone wrote:
 
 Check if the variable is a pointer, and if yes, dereference it:

 alias typeof(i) T;
 static if (is(T T2 : T2*)) {
 T2 i2 = *i;
 Format.convert("{}", i2);
 } else {
 Format.convert("{}", i);
 }


 Hi again,
 
 I cannot compile this code 


What exactly are you doing? What do you want to do? Without knowing 
this, we can only guess. My first reply to you was also just a guess. I 
thought maybe you had a templated function, and wanted to dump a 
templated variable, or so.

Anyway, here's a complete version of my example above. It uses 
Stdout.formatln instead of Format.convert, but this shouldn't matter at all.

import tango.io.Stdout;

void main() {

     int v = 55;
     int *pv = &v;

     //pv (an int pointer) can be exchanged with v (an int),
     //and it still works
     auto i = pv;

     alias typeof(i) T;
     static if (is(T T2 : T2*)) {
         T2 i2 = *i;
         Stdout.formatln("{}", i2);
     } else {
         Stdout.formatln("{}", i);
     }

}

Qian Xu <quian.xu stud.tu-ilmenau.de> writes:

grauzone wrote:

 mport tango.io.Stdout;
 
 void main() {
 
 int v = 55;
 int *pv = &v;
 
 //pv (an int pointer) can be exchanged with v (an int),
 //and it still works
 auto i = pv;
 
 alias typeof(i) T;
 static if (is(T T2 : T2*)) {
 T2 i2 = *i;
 Stdout.formatln("{}", i2);
 } else {
 Stdout.formatln("{}", i);
 }
 
 }



Thanks. Now I understood your code. ^^)

Frank Benoit <keinfarbton googlemail.com> writes:

Qian Xu schrieb:
 Hi All,
 
 tango.text.convert.Format provides a nice function to convert anything
 to string.
 
 It works perfect except the argument is a pointer type.
 It will print the address of a pointer instead of its value
 
 For instance: --------------------------------
 int* i = new int;
 *i = 10;
 Format.convert("{}", i); // <- the address of the pointer
 ----------------------------------------------
 
 How to let it print the value instead of the address?
 Because I wanna write a dump function to dump the value of any data type
 (also void, null)
 
 
 
 


This is not really an exact answer to your question... :)
It seems you want to output trace information. Stdout (which seems you
are using) is not thread safe and will generate AV/segf if accessed
concurrently.
Specially for printing trace info, there is
tango.util.log.Trace
it is a Stdout replacement that is synchronized, and it also has a
memory() function, that lets you print raw memory as a dump.