我怎样才能组织C ++代码而不用太费力地思考是否有模板化的东西？

Question

(I feel like this must be a duplicate, but I can't find it).

Consider:

airplane.hpp:

template<class T>
void wings();

void tail();

Now... where to define wings() and tail() ? I'd like to define them in the same place; I'd like not to think about the fact that wings() is templated and tail() isn't. Maybe you'll see why I sometimes write:

airplane.hpp:

template<class T>
void wings();

void tail();

#ifndef airplane_cpp
#define header
#endif
#include "airplane.cpp"

airplane.cpp:

#define airplane_cpp
#include "airplane.hpp"

template<class T>
void wings() { }

#ifndef header
void tail() { }
#endif

But surely that's not the best way.

edit: It seems it may be relevant to add that I'm programming on a TI DSP chip, where, according to the docs , the inline keyword has a defined consequence on generated code:

The inline keyword specifies that a function is expanded inline at the point at which it is called rather than by using standard calling procedures. The compiler performs inline expansion of functions declared with the inline keyword.

Answer 1

You can define all the functions in the header if you make them inline :

template<class T>
inline void wings() {}
// inline not really needed here, but if you don't want to think about it...

inline void tail() {}

Answer 2

What you want can be achieved using the keyword export in front of your template. Unfortunately this keyword has not gained considerable support across compilers.

In other words, practically speaking, you should define the body of your template in the header file.

From my point of view, compiler vendors should have do an effort to implement the same paradigm that is used for functions also for for templates. Ie description of the interface should stay in the header files, description of the bodies bodies in cpp files. Everything should be combined together during linking. They has not done this. As we have it today, paradigms for functions and tempates are different. Templates are compile time ony entities.