• Brian (9/9) Dec 04 2008 Is it safe to cast a function(or delegate) into one that takes more
• Jarrett Billingsley (4/13) Dec 04 2008 No. According to the D ABI, the callee cleans the stack. So if you
• Denis Koroskin (6/15) Dec 04 2008 Try using type-safe alternatives:
• Jarrett Billingsley (2/20) Dec 04 2008 That's only safe in the context of the declaring function, in D1 at leas...

Brian <digitalmars brianguertin.com> writes:

Is it safe to cast a function(or delegate) into one that takes more 
arguments, causing those arguments to be ignored?
Example:

void fn() {
}

auto fptr = cast(void function(int, int))&fn;
fptr(1, 2);

// It seems to work with a simple test case, I'm just afraid of it 
blowing up at me later on.

"Jarrett Billingsley" <jarrett.billingsley gmail.com> writes:

On Thu, Dec 4, 2008 at 10:37 AM, Brian <digitalmars brianguertin.com> wrote:
 Is it safe to cast a function(or delegate) into one that takes more
 arguments, causing those arguments to be ignored?
 Example:

 void fn() {
 }

 auto fptr = cast(void function(int, int))&fn;
 fptr(1, 2);

 // It seems to work with a simple test case, I'm just afraid of it
 blowing up at me later on.

No.  According to the D ABI, the callee cleans the stack.  So if you
pass more parameters than the function expects, you'll end up trashing
the stack by leaving extra values on it.

"Denis Koroskin" <2korden gmail.com> writes:

On Thu, 04 Dec 2008 18:37:10 +0300, Brian <digitalmars brianguertin.com>  
wrote:

 Is it safe to cast a function(or delegate) into one that takes more
 arguments, causing those arguments to be ignored?
 Example:

 void fn() {
 }

 auto fptr = cast(void function(int, int))&fn;
 fptr(1, 2);

 // It seems to work with a simple test case, I'm just afraid of it
 blowing up at me later on.

Try using type-safe alternatives:

auto fptr = (int,int) {
     fn();
}

"Jarrett Billingsley" <jarrett.billingsley gmail.com> writes:

On Thu, Dec 4, 2008 at 12:23 PM, Denis Koroskin <2korden gmail.com> wrote:
 On Thu, 04 Dec 2008 18:37:10 +0300, Brian <digitalmars brianguertin.com>
 wrote:

 Is it safe to cast a function(or delegate) into one that takes more
 arguments, causing those arguments to be ignored?
 Example:

 void fn() {
 }

 auto fptr = cast(void function(int, int))&fn;
 fptr(1, 2);

 // It seems to work with a simple test case, I'm just afraid of it
 blowing up at me later on.

 Try using type-safe alternatives:

 auto fptr = (int,int) {
    fn();
 }

That's only safe in the context of the declaring function, in D1 at least.