Add DANG_WERROR option and use it in CI. (#48)

* Add DANG_WERROR option and use it in CI.

* Fix conversion warning.

Author: Possseidon

.github/workflows/run-build-and-tests.yml

@@ -68,7 +68,7 @@ jobs:
         uses: ilammy/msvc-dev-cmd@v1
 
       - name: Install dependencies and generate project files
-        run: cmake -S "${{github.workspace}}" -B "${{env.CMAKE_BUILD_DIR}}" -GNinja -DCMAKE_TOOLCHAIN_FILE="${{env.VCPKG_ROOT}}/scripts/buildsystems/vcpkg.cmake"
+        run: cmake -S "${{github.workspace}}" -B "${{env.CMAKE_BUILD_DIR}}" -GNinja -DCMAKE_TOOLCHAIN_FILE="${{env.VCPKG_ROOT}}/scripts/buildsystems/vcpkg.cmake" -DDANG_WERROR:BOOL=ON
 
       - name: Build all
         run: cmake --build "${{env.CMAKE_BUILD_DIR}}"

CMakeLists.txt

@@ -4,8 +4,10 @@ project(dang-lib VERSION 0.1.0 LANGUAGES CXX)
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/cmake" ${CMAKE_MODULE_PATH})
 
+option(DANG_WERROR "Whether to treat warnings as errors.")
+
 if(MSVC)
-  add_compile_options(/W4 /bigobj)
+  add_compile_options(/W4 /bigobj "$<$<BOOL:${DANG_WERROR}>:/WX>")
   if(${CMAKE_CXX_COMPILER_ID} STREQUAL "Clang")
     add_compile_options(
       "SHELL:-Xclang -Wno-missing-braces"
@@ -14,7 +16,7 @@ if(MSVC)
   endif()
   add_compile_definitions("DANG_DLLEXPORT=__declspec(dllexport)")
 else()
-  add_compile_options(-Wall -Wextra -pedantic)
+  add_compile_options(-Wall -Wextra -pedantic "$<$<BOOL:${DANG_WERROR}>:-Werror>")
   add_compile_definitions("DANG_DLLEXPORT=__attribute__((visibility(\"default\")))")
 endif()
 

dang-math/lua/src/lua-geometry.cpp

@@ -8,7 +8,7 @@ namespace dang::lua {
 
 namespace detail {
 
-void checkIndex(State& lua, int arg, int index, int size)
+void checkIndex(State& lua, int arg, std::size_t index, std::size_t size)
 {
     if (index < 1 || index > size)
         lua.argError(arg,