* Add Appveyor CI script

* fix VS2017 Compile issues

.appveyor.yml

@@ -0,0 +1,22 @@
+version: "{build}"
+
+os: Visual Studio 2017
+
+platform:
+  - x64
+
+build:
+  parallel: true  # enable MSBuild parallel builds
+  verbosity: minimal
+
+install:
+  - if not exist llvm.tar.xz appveyor DownloadFile "https://ziglang.org/deps/llvm+clang-7.0.0-win64-msvc-release.tar.xz" -FileName llvm.tar.xz
+  - 7z e -txz llvm.tar.xz
+  - 7z x llvm.tar
+  - git submodule update --init --recursive
+build_script: 
+  - cmake -G"Visual Studio 15 2017 Win64" -H. -Bbuild -DCMAKE_BUILD_TYPE=Release -DSYSTEM_CLANG=ON -DCLANG_ROOT=C:\projects\ccls\llvm+clang-7.0.0-win64-msvc-release
+  - cmake --build build --target ccls --config Release
+
+artifacts:
+  - path: build\Release

CMakeLists.txt

@@ -58,8 +58,11 @@ if(MSVC)
             # roughly -Wno-sign-compare
     /wd4800
     /wd4068 # Disable unknown pragma warning
+    /std:c++17
     $<$<CONFIG:Debug>:/FS>
   )
+  # relink system libs
+  target_link_libraries(ccls PRIVATE Mincore.lib)
 else()
   # Common GCC/Clang(Linux) options
   target_compile_options(ccls PRIVATE

cmake/FindClang.cmake

@@ -143,9 +143,10 @@ if(Clang_FOUND AND NOT TARGET Clang::Clang)
   set_target_properties(Clang::Clang PROPERTIES
     IMPORTED_LOCATION ${Clang_LIBRARY}
     INTERFACE_INCLUDE_DIRECTORIES "${Clang_INCLUDE_DIR};${Clang_BUILD_INCLUDE_DIR};${LLVM_INCLUDE_DIR};${LLVM_BUILD_INCLUDE_DIR}")
-
-  find_package(Curses REQUIRED)
-  find_package(ZLIB REQUIRED)
+  if(NOT WIN32)
+    find_package(Curses REQUIRED)
+    find_package(ZLIB REQUIRED)
+  endif()
   set_property(TARGET Clang::Clang PROPERTY IMPORTED_LINK_INTERFACE_LIBRARIES "${_Clang_LIBRARIES};${CURSES_LIBRARIES};${ZLIB_LIBRARIES}")
   if(MINGW)
     set_property(TARGET Clang::Clang APPEND_STRING PROPERTY IMPORTED_LINK_INTERFACE_LIBRARIES ";version")

src/position.hh

@@ -76,6 +76,7 @@ namespace std {
 template <> struct hash<ccls::Range> {
   std::size_t operator()(ccls::Range x) const {
     union U {
+      U() {} // On VS2017, still need constructor here
       ccls::Range range = {};
       uint64_t u64;
     } u;