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.

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.

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();
}

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.