PFAX_ROUTING_INSTALLATION_CALLBACKW should take PWSTR instead of PCWSTR

[fnetz]

Summary

The last four parameters are "out" LPWSTR parameters according to the API doc, and probably shouldn't be PCWSTR.

This seems Rust specific, for example the Python and Beef libraries do use PWSTR.

Crate manifest

[dependencies]
windows = { version = "0.52.0", features = ["Win32_Foundation", "Win32_Devices_Fax"] }

Crate code

extern "system" fn register_callback(
    fax_handle: HANDLE,
    context: *mut c_void,
    method_name_out: PCWSTR,
    friendly_name_out: PCWSTR,
    function_name_out: PCWSTR,
    guid_out: PCWSTR,
) -> BOOL {
    // The callback is supposed to write to method_name_out, etc.
}

FaxRegisterRoutingExtensionW(handle, extension_name, friendly_name, image_name, Some(register_callback), context);

[kennykerr]

Looks like these are in/out parameters but the Win32 metadata is indicating they are in-only.

typedef BOOL
(CALLBACK *PFAX_ROUTING_INSTALLATION_CALLBACKW)(
    IN HANDLE FaxHandle,
    IN LPVOID Context,
    IN OUT LPWSTR MethodName,
    IN OUT LPWSTR FriendlyName,
    IN OUT LPWSTR FunctionName,
    IN OUT LPWSTR Guid
    );

Will transfer for consideration.