Change build code to be maximally pedantic

CMakeLists.txt

@@ -1,6 +1,10 @@
 cmake_minimum_required(VERSION 3.16)
 project(lispy_stuff)
 
+# we'll use a recent c++ standard.
+set(CMAKE_CXX_STANDARD 23)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
 # we'll use catch2 as testing library.
 include(FetchContent)
 FetchContent_Declare(
@@ -14,17 +18,21 @@ include(Catch)
 
 set(HEADER_FILES src/include/lex.hpp)
 set(SOURCE_FILES src/lex.cpp)
+set(CXX_WARNING_FLAGS -Wall -Wextra -Wpedantic -pedantic -Werror)
 
 # we're not actually shipping a library yet,
 # this is so we don't have to compile twice for main and tests.
 add_library(libmash STATIC ${SOURCE_FILES} ${HEADER_FILES})
 target_include_directories(libmash PUBLIC src/include/)
+target_compile_options(libmash PRIVATE ${CXX_WARNING_FLAGS})
 
 # Main target
 add_executable(main src/main.cpp)
 target_link_libraries(main libmash)
+target_compile_options(main PRIVATE ${CXX_WARNING_FLAGS})
 
 # tests
 add_executable(test src/tests/test.cpp)
 target_link_libraries(test PRIVATE libmash Catch2::Catch2WithMain)
+target_compile_options(test PRIVATE ${CXX_WARNING_FLAGS})