meson: Basic meson support (CLIUtils#299)

* meson: Basic meson support

With this patch, CLI11 can be used as a meson
subproject: http://mesonbuild.com/Subprojects.html

However, CMake is still required for testing and
installation. The current meson.build is not a
complete replacement.

* meson: Added meson test

* Adding Azure test

.gitignore

@@ -5,3 +5,5 @@ a.out*
 /Makefile
 /CMakeFiles/*
 /cmake_install.cmake
+/*.kdev4
+!/meson.build

azure-pipelines.yml

@@ -48,6 +48,22 @@ jobs:
     - template: .ci/azure-build.yml
     - template: .ci/azure-test.yml
 
+- job: Meson
+  pool:
+    vmImage: 'ubuntu-latest'
+  steps:
+    - task: UsePythonVersion@0
+      inputs:
+        versionSpec: '3.6'
+    - script: python3 -m pip install meson ninja
+    - script: meson build
+      displayName: Run meson to generate build
+      workingDirectory: tests/mesonTest
+    - script: ninja -C tests/mesonTest/build
+      displayName: Build with Ninja
+    - script: ./tests/mesonTest/build/main --help
+      displayName: Run help
+
 - job: Docker
   variables:
     cli11.single: OFF

meson.build

@@ -0,0 +1,11 @@
+project('CLI11', ['cpp'],
+  version         : run_command(find_program('scripts/ExtractVersion.py')).stdout().strip(),
+  default_options : ['cpp_std=c++11']
+)
+
+CLI11_inc = include_directories(['include'])
+
+CLI11_dep = declare_dependency(
+  include_directories : CLI11_inc,
+  version             : meson.project_version(),
+)

scripts/ExtractVersion.py

@@ -0,0 +1,17 @@
+#!/usr/bin/env python3
+
+import os
+import re
+
+base_path = os.path.abspath(os.path.join(os.path.dirname(__file__), '..'))
+config_h  = os.path.join(base_path, 'include', 'CLI', 'Version.hpp')
+data      = {'MAJOR': 0, 'MINOR': 0, 'PATCH': 0}
+reg       = re.compile(r'^\s*#define\s+CLI11_VERSION_([A-Z]+)\s+([0-9]+).*$')
+
+with open(config_h, 'r') as fp:
+  for l in fp:
+    m = reg.match(l)
+    if m:
+      data[m.group(1)] = int(m.group(2))
+
+print('{}.{}.{}'.format(data['MAJOR'], data['MINOR'], data['PATCH']))

tests/mesonTest/README.md

@@ -0,0 +1,10 @@
+# CLI11 Meson test / example
+
+Requirements: meson, ninja
+
+## Build
+
+```bash
+meson build
+ninja -C build
+```

tests/mesonTest/main.cpp

@@ -0,0 +1,11 @@
+#include <CLI/CLI.hpp>
+
+int main(int argc, char **argv) {
+    CLI::App app{"App description"};
+
+    std::string filename = "default";
+    app.add_option("-f,--file", filename, "A help string");
+
+    CLI11_PARSE(app, argc, argv);
+    return 0;
+}

tests/mesonTest/meson.build

@@ -0,0 +1,5 @@
+project('mesonTest', ['c', 'cpp'], default_options: ['cpp_std=c++11'])
+
+cli11_dep = subproject('CLI11').get_variable('CLI11_dep')
+
+mainExe = executable('main', ['main.cpp'], dependencies: [cli11_dep])

tests/mesonTest/subprojects/CLI11

@@ -0,0 +1 @@
+../../..