Don't use std::result_of

It's removed in C++20

Bug: 175635923
Test: m libidlcli
Test: m lshal
Change-Id: I4301ad34a1c5db73530cefdbba3968bc3ac3c0a2

cmds/idlcli/vibrator.h

@@ -74,7 +74,7 @@ inline auto getService<android::hardware::vibrator::V1_3::IVibrator>(std::string
 }
 
 template <typename I>
-using shared_ptr = std::result_of_t<decltype(getService<I>)&(std::string)>;
+using shared_ptr = std::invoke_result_t<decltype(getService<I>)&, std::string>;
 
 template <typename I>
 class HalWrapper {

cmds/lshal/Timeout.h

@@ -30,7 +30,7 @@ namespace lshal {
 // has returned, especially if deadline has been reached. Hence, care must be taken when passing
 // data between the background thread and the main thread. See b/311143089.
 template<class R, class P, class Function, class I, class... Args>
-typename std::result_of<Function(I *, Args...)>::type
+typename std::invoke_result<Function, I *, Args...>::type
 timeoutIPC(std::chrono::duration<R, P> wait, const sp<I> &interfaceObject, Function &&func,
            Args &&... args) {
     using ::android::hardware::Status;