• Frank Benoit (keinfarbton) (7/7) Feb 24 2007 I want to assign a function ptr to a void* variable.
• Jarrett Billingsley (6/13) Feb 24 2007 Yes, that does seem to choose the (int) overload. Although what's reall...
• Chris Nicholson-Sauls (5/25) Feb 24 2007 And now one of the classic proposals, once again. :)
• Frank Benoit (keinfarbton) (6/9) Feb 26 2007 Is this perhaps a problem with context free syntax?
• BCS (6/19) Feb 26 2007 The "address of" should resolve that because you can't take the address ...
• Frank Benoit (keinfarbton) (2/5) Feb 24 2007 posted:
• Kirk McDonald (11/33) Feb 24 2007 What we really need is a way to get a tuple of all of the function types...

"Frank Benoit (keinfarbton)" <benoit tionex.removethispart.de> writes:

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;

"Jarrett Billingsley" <kb3ctd2 yahoo.com> writes:

"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.. 

Chris Nicholson-Sauls <ibisbasenji gmail.com> writes:

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

"Frank Benoit (keinfarbton)" <benoit tionex.removethispart.de> writes:

 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.

BCS <ao pathlink.com> writes:

Reply to Frank,

 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.
 

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.

"Frank Benoit (keinfarbton)" <benoit tionex.removethispart.de> writes:

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

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

Kirk McDonald <kirklin.mcdonald gmail.com> writes:

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