const std = @import("std"); const windows = std.os.windows; // This declares a function named `retrowin32_callback1` exists in `retrowin32.dll`, // which is true in the emulator enivronment because the emulator exposes this function // just for this program. See win32/lib/ for related support files. pub extern "retrowin32_test" fn retrowin32_test_callback1( func: *const fn (u32) callconv(.Stdcall) u32, data: u32, ) callconv(windows.WINAPI) u32; fn callback0(data: u32) callconv(windows.WINAPI) u32 { std.debug.print("callback0 invoked: {x}\n", .{data}); return 0x4567; } pub fn main() !void { const ret = retrowin32_test_callback1(callback0, 0x1234); std.debug.print("retrowin32_callback1 returned: {x}\n", .{ret}); }