• "Frank Benoit (keinfarbton)" <benoit tionex.removethispart.de> Feb 24 2007
• "Jarrett Billingsley" <kb3ctd2 yahoo.com> Feb 24 2007
• Chris Nicholson-Sauls <ibisbasenji gmail.com> Feb 24 2007
• "Frank Benoit (keinfarbton)" <benoit tionex.removethispart.de> Feb 26 2007
• BCS <ao pathlink.com> Feb 26 2007
• "Frank Benoit (keinfarbton)" <benoit tionex.removethispart.de> Feb 24 2007
• Kirk McDonald <kirklin.mcdonald gmail.com> Feb 24 2007

I want to assign a function ptr to a void* variable.

There are no compile error in case the function is a overloaded one. Is
this a bug?

How to select the correct function? I tried a cast, and it seams to work.

void fnc(){}
void fnc(int a ){}

void * ptr = cast(void*)cast( void function( int )) & fnc;

"Frank Benoit (keinfarbton)" <benoit tionex.removethispart.de> wrote in 
message news:erpk4o$1oom$1 digitalmars.com...
I want to assign a function ptr to a void* variable.

 There are no compile error in case the function is a overloaded one. Is
 this a bug?

 How to select the correct function? I tried a cast, and it seams to work.

 void fnc(){}
 void fnc(int a ){}

 void * ptr = cast(void*)cast( void function( int )) & fnc;


Yes, that does seem to choose the (int) overload.  Although what's really 
odd is that getting the address of fnc without any cast before it gets the 
address of the overload that was defined first.  Personally I think it 
should be an error, as it's ambiguous.. 

Jarrett Billingsley wrote:
 "Frank Benoit (keinfarbton)" <benoit tionex.removethispart.de> wrote in 
 message news:erpk4o$1oom$1 digitalmars.com...
 I want to assign a function ptr to a void* variable.

 There are no compile error in case the function is a overloaded one. Is
 this a bug?

 How to select the correct function? I tried a cast, and it seams to work.

 void fnc(){}
 void fnc(int a ){}

 void * ptr = cast(void*)cast( void function( int )) & fnc;


 Yes, that does seem to choose the (int) overload.  Although what's really 
 odd is that getting the address of fnc without any cast before it gets the 
 address of the overload that was defined first.  Personally I think it 
 should be an error, as it's ambiguous.. 
 
 


And now one of the classic proposals, once again.  :)

void* ptr = cast(void*) &fnc(int) ;

So nice, so concise.

-- Chris Nicholson-Sauls

 And now one of the classic proposals, once again.  :)
 
 void* ptr = cast(void*) &fnc(int) ;


Is this perhaps a problem with context free syntax?
It is not clear, if this is a "get function pointer address" or a "call
function" operation.

void* ptr = cast(void*) &fnc( Something ) ;

To decide this, the compiler needs to have the arguments completely
resolved. Then he can see if they are types, or not.

Reply to Frank,

 And now one of the classic proposals, once again.  :)
 
 void* ptr = cast(void*) &fnc(int) ;
 


 It is not clear, if this is a "get function pointer address" or a
 "call
 function" operation.
 void* ptr = cast(void*) &fnc( Something ) ;
 
 To decide this, the compiler needs to have the arguments completely
 resolved. Then he can see if they are types, or not.
 


The "address of" should resolve that because you can't take the address of 
a return. OTOH that would introduce L-value/R-value into the grammar. Maybe 
the syntax of a function call could allow a type list or an expression list 
(but not a mixed list) and then the semantics would sort it out later. Bahh, 
The more I think about this stuff the more I respect Walter.

 Personally I think it 
 should be an error, as it's ambiguous.. 
 


http://d.puremagic.com/issues/show_bug.cgi?id=1006

Jarrett Billingsley wrote:
 "Frank Benoit (keinfarbton)" <benoit tionex.removethispart.de> wrote in 
 message news:erpk4o$1oom$1 digitalmars.com...
 
I want to assign a function ptr to a void* variable.

There are no compile error in case the function is a overloaded one. Is
this a bug?

How to select the correct function? I tried a cast, and it seams to work.

void fnc(){}
void fnc(int a ){}

void * ptr = cast(void*)cast( void function( int )) & fnc;


 
 Yes, that does seem to choose the (int) overload.  Although what's really 
 odd is that getting the address of fnc without any cast before it gets the 
 address of the overload that was defined first.  Personally I think it 
 should be an error, as it's ambiguous.. 
 
 


What we really need is a way to get a tuple of all of the function types 
associated with a given symbol. Something like:

fnc.tupleof => Tuple!(void function(), void function(int))

Making the above an error without providing a mechanism like this would 
adversely affect Pyd, for example.

-- 
Kirk McDonald
http://kirkmcdonald.blogspot.com
Pyd: Connecting D and Python
http://pyd.dsource.org