Inherit cpp version number (#3211)

cpp/CMakeLists.txt

@@ -18,12 +18,6 @@ cmake_minimum_required (VERSION 3.11)
 
 project (libphonenumber VERSION 8.13.0)
 
-# Pick the C++ standard to compile with.
-# Abseil currently supports C++11, C++14, and C++17.
-set(CMAKE_CXX_STANDARD 11 CACHE STRING "C++ standard used to compile this project")
-set(CMAKE_CXX_STANDARD_REQUIRED ON)
-set(CMAKE_POSITION_INDEPENDENT_CODE TRUE)
-
 if (32BIT)
   set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -m32")
   set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -m32")

tools/cpp/CMakeLists.txt

@@ -16,11 +16,6 @@
 
 cmake_minimum_required (VERSION 3.11)
 
-# Pick the C++ standard to compile with.
-# Abseil currently supports C++11, C++14, and C++17.
-set(CMAKE_CXX_STANDARD 11)
-set(CMAKE_CXX_STANDARD_REQUIRED ON)
-
 project (generate_geocoding_data)
 
 set (