Added explicit thread dependency.

dependencies.py

@@ -1059,6 +1059,16 @@ class ExtraFrameworkDependency(Dependency):
     def found(self):
         return self.name is not None
 
+class ThreadDependency(Dependency):
+    def __init__(self, environment, kwargs):
+        super().__init__()
+        self.name = 'threads'
+        self.is_found = True
+        mlog.log('Dependency', mlog.bold(self.name), 'found:', mlog.green('YES'))
+
+    def need_threads(self):
+        return True
+
 def get_dep_identifier(name, kwargs):
     elements = [name]
     modlist = kwargs.get('modules', [])
@@ -1108,4 +1118,5 @@ packages = {'boost': BoostDependency,
             'wxwidgets' : WxDependency,
             'sdl2' : SDL2Dependency,
             'gl' : GLDependency,
+            'threads' : ThreadDependency,
            }

test cases/common/102 threads/meson.build

@@ -0,0 +1,7 @@
+project('threads', 'cpp')
+
+test('threadtest',
+  executable('threadprog', 'threadprog.cpp',
+    dependencies : dependency('threads')
+  )
+)

test cases/common/102 threads/threadprog.cpp

@@ -0,0 +1,14 @@
+#include<thread>
+#include<cstdio>
+
+void main_func() {
+    printf("Printing from a thread.\n");
+}
+
+int main(int, char**) {
+    printf("Starting thread.\n");
+    std::thread th(main_func);
+    th.join();
+    printf("Stopped thread.\n");
+    return 0;
+}