Hide implementation in header-only library

Question

I've tried to use an implementation namespace, but when i 'using namespace' it, it pulls in the whole implementation namespace, rendering it useless.

namespace library {
 namespace implementation {
  //implementation
 }

 using namespace implementation

 //visible identifiers
}

Is there way to hide implementation, without needing to use "implementation::" before using anything from implementation?

Don't use `using namespace implementation;`? – NathanOliver May 27 '16 at 13:42 — NathanOliver, May 27 '16 at 13:42

score 9 · Accepted Answer · answered May 27 '16 at 13:42

9

rendering it useless

Well, it's not useless, you just can't using namespace it. You have to explicitly prepend implementation:: to the names in it. For this reason, it might make sense to choose a shorter name (detail is commonly used in c++ projects for this purpose).

Also, I'd like to point out that header-only and implementation hiding are two somewhat conflicting requirements. If you truly need to hide the implementation, you can't go header-only.

answered May 27 '16 at 13:42

Tamás Szelei

23,169
18
105
180

Ok, then i'll use macros (which i'll undef at the end of the header) to prepend identifiers from implementation. – G_glop May 27 '16 at 13:45
4

@G_glop it's your code, but I don't see an advantage of using a macro for this. – Tamás Szelei May 27 '16 at 13:46
Just a thought, maybe only for some widely used types. – G_glop May 27 '16 at 13:58

Hide implementation in header-only library

1 Answers1