message: Add C++14, C++17, and C++20 builds with VS2019.
diff: -image:
  - - Visual Studio 2015
  - - Visual Studio 2017
  - - Visual Studio 2019
  -
  configuration:
  - Debug
  @@ -11,10 +6,42 @@ build:
  environment:
  matrix:
  - - GENERATOR_ARCH: Win32
  + - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
  + GENERATOR_ARCH: Win32
  + PYTHON: "C:\\Python38"
  + CXX_STANDARD: 11
  + - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
  + GENERATOR_ARCH: x64
  + PYTHON: "C:\\Python38-x64"
  + CXX_STANDARD: 11
  + - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
  + GENERATOR_ARCH: Win32
  + PYTHON: "C:\\Python38"
  + CXX_STANDARD: 11
  + - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
  + GENERATOR_ARCH: x64
  + PYTHON: "C:\\Python38-x64"
  + CXX_STANDARD: 11
  + - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
  + GENERATOR_ARCH: Win32
  PYTHON: "C:\\Python38"
  - - GENERATOR_ARCH: x64
  + CXX_STANDARD: 11
  + - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
  + GENERATOR_ARCH: x64
  + PYTHON: "C:\\Python38-x64"
  + CXX_STANDARD: 11
  + - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
  + GENERATOR_ARCH: x64
  + PYTHON: "C:\\Python38-x64"
  + CXX_STANDARD: 14
  + - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
  + GENERATOR_ARCH: x64
  + PYTHON: "C:\\Python38-x64"
  + CXX_STANDARD: 17
  + - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
  + GENERATOR_ARCH: x64
  PYTHON: "C:\\Python38-x64"
  + CXX_STANDARD: 20
  install:
  - git submodule update --init --recursive
  @@ -32,4 +59,5 @@ build_script:
  -DSAMPLES_BUILD_WITH_LOCAL_VULKAN_HPP=ON
  -DTESTS_BUILD_ONLY_DYNAMIC=ON
  -DTESTS_BUILD_WITH_LOCAL_VULKAN_HPP=ON
  + -DCMAKE_CXX_STANDARD=%CXX_STANDARD%
  - cmake --build . --config %CONFIGURATION%
  