Use C++17 (#157)

Summary:
Dependencies started using C++17 so it's required by now and it seems there is some ABI breakage with fizz.

Pull Request resolved: #157

Reviewed By: yangchi

Differential Revision: D23454865

Pulled By: mjoras

fbshipit-source-id: 5e41ccab5cd05d1029c53a5e04e4fd2102bafd79

CMakeLists.txt

@@ -5,9 +5,12 @@
 
 cmake_minimum_required(VERSION 3.10)
 
-project(
-  mvfst
-)
+project(mvfst)
+
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
+
 set(CMAKE_MODULE_PATH
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake"
   # for in-fbsource builds
@@ -76,11 +79,6 @@ else()
   list(APPEND CMAKE_REQUIRED_INCLUDES ${LIBGFLAGS_INCLUDE_DIR})
 endif()
 
-list(APPEND
-  _QUIC_BASE_COMPILE_OPTIONS
-  -std=c++14
-)
-
 if(NOT CMAKE_SYSTEM_NAME STREQUAL "Windows")
 list(APPEND
   _QUIC_BASE_COMPILE_OPTIONS