minizip bindings

[mantielero]

As I mentioned in some posts before, I am trying to create some bindings to a C 
library (for the sake of learning). I am not very familiar with C/C++, so you 
might expect many trivial questions. I will try to keep all my questions in 
this thread.

>From other posts, it looks like a sensible thing to do is to use 
>[nimterop](https://github.com/nimterop/nimterop) over the header.

When I run:
    
    
    toast -p -r zlib-1.2.11/contrib/minizip/unzip.h > unzip_full.h

I get something like:
    
    
    #define _unz64_H
    extern "C" {
    #define Z_BZIP2ED 12
    typedef voidp unzFile;
    #define UNZ_OK (0)
    #define UNZ_END_OF_LIST_OF_FILE (-100)
    
    Run

I don't know why I am getting the second line `extern "C" {`. The header used 
contains:
    
    
    #ifdef __cplusplus
    extern "C" {
    #endif
    
    Run

If I don't have defined `__cplusplus`, I understand that the line shouldn't be 
exported. What am I missing?