Bump to C++20

Author: LebedevRI

.clang-format

@@ -1,7 +1,7 @@
 ---
 Language:     Cpp
 BasedOnStyle: LLVM
-Standard:     c++17
+Standard:     c++20
 # Force pointers to the type for C++.
 DerivePointerAlignment: false
 PointerAlignment: Left

cmake/compiler-flags.cmake

@@ -1,6 +1,6 @@
 include(CpuMarch)
 
-set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
 

cmake/src-dependencies.cmake

@@ -16,7 +16,7 @@ if(BUILD_BENCHMARKING)
   add_dependencies(dependencies benchmark)
 endif()
 
-target_compile_features(rawspeed PUBLIC cxx_std_17)
+target_compile_features(rawspeed PUBLIC cxx_std_20)
 
 unset(HAVE_OPENMP)
 if(WITH_OPENMP)