[Development] Binary Compatibility question (KDE)

[Christoph Feck]

On Thursday 27 February 2014 21:06:04 Tony Van Eerd wrote:
> Sorry, there is probably a KDE email list or something that I
> should post this to, but I know it is very closely related to Qt:
> 
> On
> http://techbase.kde.org/Policies/Binary_Compatibility_Issues_With_
> C%2B%2B there is:
> 
> You cannot...
> 
> - For existing functions of any type:
> 	- add an overload (BC, but not SC: makes &func ambiguous), 
adding
> overloads to already overloaded functions is ok (any use of &func
> already needed a cast).
> 
> There is another issue - implicit casting. ie
> 
> Foo.hpp // old
> 	int foo(const char * ptr);
> 
> MyCode.cpp
> 	#include <Foo.hpp>
> 	int x = foo(NULL);
> 
> 
> Foo.hpp // NEW (1)
> 	int foo(const char * ptr);
> 	int foo(Bar *);
> 
> MyCode (same as above) now has SC break - "ambiguous function 
call"
> 
> Foo.hpp  // NEW(2) - WORSE
> 	int foo(const char * ptr);
> 	int foo(int);
> 
> MyCode.cpp now still compiles, *but calls a different function!* - 
> foo(int), as NULL is 0 is an int, and that is a closer match that
> foo(const char *).
> 
> 
> Anyone care?  Where should I forward this email to?
> 
> Thanks,
> Tony

You are right, but what is your actual question?

Christoph Feck (kdepepo)
KDE Quality Team