Template Function use as function argument problem,thanks.

[linarin]

#include <iostream>
using namespace std;

typedef bool (*CallableFunct ion)(int argc,char* argv[]);

void DefineMyFunctio n(const char* name,CallableFu nction func){
//here do the define action.
}

template<typena me R,typename A,R (*pFunc)(A)>
bool CallableFunctio nProxy(int argc,char* argv[]){
A a = A(); // this is demo only
pFunc(a);
return true;
}

template<typena me R,typename A>
void Def(const char* name,R (*pFunc)(A)){
DefineMyFunctio n(name,Callable FunctionProxy<R ,A,pFunc>);
}

int alert(int){
cout << "From alert" << endl;
return 0;
}

int main(int argc,char* argv[])
{
CallableFunctio nProxy<int,int, alert>(argc,arg v);
//Def("alert",ale rt); //error here
return 0;
}
this program compile and execute as respected.
but when I uncomment the line marked with "error here" in function
"main" the following compile error occur, could any one known what is
error:

D:\Program\Code Blocks\Projects \firstCpp\main. cpp:29: instantiated from
here
D:\Program\Code Blocks\Projects \firstCpp\main. cpp:18: error: `pFunc' is
not a valid template argument
D:\Program\Code Blocks\Projects \firstCpp\main. cpp:18: error: it must be
the address of a function with external linkage
D:\Program\Code Blocks\Projects \firstCpp\main. cpp:18: error: `pFunc' is
not a valid template argument
D:\Program\Code Blocks\Projects \firstCpp\main. cpp:18: error: it must be
the address of a function with external linkage
D:\Program\Code Blocks\Projects \firstCpp\main. cpp:18: error: `pFunc' is
not a valid template argument
D:\Program\Code Blocks\Projects \firstCpp\main. cpp:18: error: it must be
the address of a function with external linkage
D:\Program\Code Blocks\Projects \firstCpp\main. cpp:18: error: no matches
converting function `CallableFuncti onProxy' to type `bool (*)(int,
char**)'
D:\Program\Code Blocks\Projects \firstCpp\main. cpp:10: error: candidates
are: template<class R, class A, R (*pFunc)(A)bool
CallableFunctio nProxy(int, char**)
:: === Build finished: 8 errors, 1 warnings ===

[dasjotre]

On 13 Jun, 07:23, linarin <lin.jian...@gm ail.comwrote:

template<typena me R,typename A>
void Def(const char* name,R (*pFunc)(A)){

pFunc here is a run-time value, it can not be used
as template parameter.

DefineMyFunctio n(name,Callable FunctionProxy<R ,A,pFunc>);

you could change Def to take pFunc as a template
parameter the same way you use it in
CallableFunctio nProxy

template<typena me R,typename A, R (*pFunc)(A)>
void Def(const char* name){
DefineMyFunctio n(name,Callable FunctionProxy<R ,A,pFunc>);
}

but then you have to call it

Def<int, int, &alert>("alert" );

(I have no idea what you're trying to achieve)
you should check boost::function (or std::tr1::funct ion
if you have tr1)

DS

[linarin]

Oh,thanks.

but how boost.python is implemented. I am trying port the
boost.python to SpiderMonkey.

have you any idea?

[dasjotre]

On 14 Jun, 01:24, linarin <lin.jian...@gm ail.comwrote:

Oh,thanks.

but how boost.python is implemented. I am trying port the
boost.python to SpiderMonkey.

have you any idea?

no, but you can download boost code and check
for yourself.

DS