ci: use appveyor for multi msvc versions

CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.22)
+cmake_minimum_required(VERSION 3.16)
 project(toml11 LANGUAGES CXX VERSION 4.0.0)
 
 include(CMakeDependentOption)

README.md

@@ -1,6 +1,7 @@
 # toml11
 
 [![Build Status on GitHub Actions](https://github.com/ToruNiina/toml11/workflows/build/badge.svg)](https://github.com/ToruNiina/toml11/actions)
+[![Build status](https://ci.appveyor.com/api/projects/status/m2n08a926asvg5mg/branch/main?svg=true)](https://ci.appveyor.com/project/ToruNiina/toml11/branch/main)
 [![Version](https://img.shields.io/github/release/ToruNiina/toml11.svg?style=flat)](https://github.com/ToruNiina/toml11/releases)
 [![License](https://img.shields.io/github/license/ToruNiina/toml11.svg?style=flat)](LICENSE)
 [![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.1209136.svg)](https://doi.org/10.5281/zenodo.1209136)

appveyor.yml

@@ -0,0 +1,26 @@
+version: "{build}"
+
+environment:
+  matrix:
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
+      generator: Visual Studio 16 2019
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2022
+      generator: Visual Studio 17 2022
+
+configuration:
+  - Release
+  - Debug
+
+clone_depth: 10
+clone_folder: c:\toml11
+
+install:
+- git submodule update --init --recursive
+
+build_script:
+  - cd C:\toml11
+  - cmake -B build -G"%generator%" -A x64 -DCMAKE_CXX_STANDARD=11 -DTOML11_BUILD_TESTS=ON -DTOML11_PRECOMPILE=ON
+  - cmake --build build --config "%configuration%"
+
+test_script:
+  - ctest --test-dir build --build-config "%configuration%" --timeout 300 --output-on-failure