I'm basically straight out of acadamia with a 4 year CS degree, so be
gentle :)
I've been working adding a Linux port to a current Windows-only project,
and I've run into what appears to be inheritance with C structs. I've
distilled the problem down to the following code:
// Test for struct inheritance
#ifdef __cplusplus
struct base
#else
typedef struct _base
#endif
{
int b;
#ifdef __cplusplus
};
#else
} base;
#endif
#ifdef __cplusplus
struct derived : public base
{
#else
typedef struct _derived
{
base;
#endif
int d;
#ifdef __cplusplus
};
#else
} derived;
#endif
int main()
{
base b;
derived d;
b.b = 5;
d.b = b.b;
d.d = 10;
return 0;
}
It is apparent that the struct is to behave the same whether compiled in
C or C++. I admit to being a bit confused to see Polymorphism in C. This
code builds and runs in my WinDDK environment for windows, as well as
for Linux g++, but Linux gcc gives me the following error:
struct_test.c:20: warning: declaration does not declare anything
struct_test.c: In function ‘main’:
struct_test.c:33: error: ‘derived’ has no member named ‘b’
That totally makes sense. The C I know doesn't have polymorphism.
So, I need to derive a solution that will be cross-platform, and
hopefully not require any changes to existing code that uses these
structs. I'm sort of holding my breath for a gcc option like
"-magic_structs". Any help or general advice is welcome.
