Question

I have problem with extremely long compiling time on my C++ code where I use some template functions from external library.

Example:

//fun.h
template <class T>
T fun(T in){
 ...
}

//main.cpp
#include fun.h
class A{...};
int main(){
A a,b;
...
b=fun<A>(a);  //this line causes the long compilation time, because fun is really complicated
...
}

I’m thinking about somehow define new function

funA := fun<A> 

in separate header file and pre-compile it. So each time I change main.cpp I don’t have to build

fun<A>

again an again. But I have no idea how to do it. I think that with classes you simply put

typedef class<A> classA;

in pre-compiled header and you are done. But how to do it with functions?

Answer 1

wrap_fun.h:

A funA(A a);

wrap_fun.C:

#include "wrap_fun.h"
#include "fun.h"

A funA(A a)
{
    return fun(a);  // Should deduce type automatically.
}