pointers to function

[devphylosoff]

#include <iostream>
#include <math.h>

using namespace std;

#define Type double

inline Type function(Type x) { return (x * exp(-2.0 * x)); }

Type Trapeze(int const n, Type (*fptr)(Type));

int main(){
int n=3;
/* a both line with cout return:

g++ -orun del.cc -lm
/tmp/ccnUqQbp.o(.text+0x2f): In function `main':
del.cc: undefined reference to `Trapeze(int, double (*)(double))'
collect2: ld returned 1 exit status

why ?! - I have definition for 'Trapeze(int, double (*)(double))'
so what is wrong ?
*/
cout << Trapeze(n, &function);
//cout << Trapeze(n, (Type(*)(Type))(function));

return 0;
}

Type trapeze(int const n, Type (*fptr)(Type)) {
Type g;
g = (*fptr)(23.8);

return g;
}

[Victor Bazarov]

devphylosoff wrote:

[...]
Type Trapeze(int const n, Type (*fptr)(Type));
Type trapeze(int const n, Type (*fptr)(Type)) {
Type g;
g = (*fptr)(23.8);

return g;
}

Compare the two lines. Can you see the difference? Do you still
think that you "have the definition for 'Trapeze'"?

V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask

[devphylosoff]

jesus, I'm a blind, sorry.