Implement redo keyboard shortcut tailored to specific OS

Question

Suppose I want to distribute my application to all these three platforms:

1. Linux
2. Windows
3. OS X

Each system tends to have their own specific keyboard shortcuts standard, for instance, on Linux redo shortcut is Ctrl + Shift + Z whereas on Windows it's Ctrl + Y

I want my application to adapt to each environment so Linux shortcuts won't be active/compiled if it's run on OS X or Windows. And vice versa.

The solution I have in mind is using macros:

#if __gnu_linux__
    application->set_accels_for_action("window.redo", "<Primary><Shift>Z");
#else
    // ...for all other platforms
    application->set_accels_for_action("window.redo", "<Primary>Y");
#endif

Is there a better way than using macros?