[Boost-commit] svn:boost r42175 - sandbox/committee/LWG/examples

From: hinnant_at_[hidden]
Date: 2007-12-19 14:10:39

Author: hinnant
Date: 2007-12-19 14:10:38 EST (Wed, 19 Dec 2007)
New Revision: 42175
URL: http://svn.boost.org/trac/boost/changeset/42175

Log:
Added native_handle_detection.cpp

Added:
   sandbox/committee/LWG/examples/native_handle_detection.cpp   (contents, props changed)

Added: sandbox/committee/LWG/examples/native_handle_detection.cpp
==============================================================================
--- (empty file)
+++ sandbox/committee/LWG/examples/native_handle_detection.cpp	2007-12-19 14:10:38 EST (Wed, 19 Dec 2007)
@@ -0,0 +1,123 @@
+#include <iostream>
+#include <string>
+#include <mutex>
+#include <condition_variable>
+#include <thread>
+
+template <class Thread>
+struct has_native_handle_type
+{
+	struct two {char x; char y;};
+	template <class U> static two  test(...);
+	template <class U> static char test(typename U::native_handle_type*);
+public:
+	static const bool value = sizeof(test<Thread>(0)) == 1;
+};
+
+template <class T, T val>
+struct member_wrapper{};
+
+template <class T>
+class has_native_handle
+{
+	struct two {char x; char y;};
+	template <class U> static two  test(...);
+	template <class U> static char test(member_wrapper<typename U::native_handle_type (U::*)(), &U::native_handle>*);
+public:
+	static const bool value = sizeof(test<T>(0)) == 1;
+};
+
+template <bool>
+struct choose
+{
+    std::string operator()() const {return std::string("not ");}
+};
+
+template <>
+struct choose<true>
+{
+    std::string operator()() const {return std::string();}
+};
+
+int main()
+{
+    std::cout << "Demonstration of automatic detection of native_handle_type and native_handle.\n";
+    std::cout << "For this implementation of the threading API:\n\n";
+
+    std::cout << "std::mutex does "
+              << choose<has_native_handle_type<std::mutex>::value>()()
+              << "have native_handle_type.\n";
+    std::cout << "std::mutex does "
+              << choose<has_native_handle<std::mutex>::value>()()
+              << "have native_handle.\n\n";
+
+    std::cout << "std::recursive_mutex does "
+              << choose<has_native_handle_type<std::recursive_mutex>::value>()()
+              << "have native_handle_type.\n";
+    std::cout << "std::recursive_mutex does "
+              << choose<has_native_handle<std::recursive_mutex>::value>()()
+              << "have native_handle.\n\n";
+
+    std::cout << "std::timed_mutex does "
+              << choose<has_native_handle_type<std::timed_mutex>::value>()()
+              << "have native_handle_type.\n";
+    std::cout << "std::timed_mutex does "
+              << choose<has_native_handle<std::timed_mutex>::value>()()
+              << "have native_handle.\n\n";
+
+    std::cout << "std::recursive_timed_mutex does "
+              << choose<has_native_handle_type<std::recursive_timed_mutex>::value>()()
+              << "have native_handle_type.\n";
+    std::cout << "std::recursive_timed_mutex does "
+              << choose<has_native_handle<std::recursive_timed_mutex>::value>()()
+              << "have native_handle.\n\n";
+
+    std::cout << "std::condition_variable does "
+              << choose<has_native_handle_type<std::condition_variable>::value>()()
+              << "have native_handle_type.\n";
+    std::cout << "std::condition_variable does "
+              << choose<has_native_handle<std::condition_variable>::value>()()
+              << "have native_handle.\n\n";
+
+    std::cout << "std::condition_variable_any does "
+              << choose<has_native_handle_type<std::condition_variable_any>::value>()()
+              << "have native_handle_type.\n";
+    std::cout << "std::condition_variable_any does "
+              << choose<has_native_handle<std::condition_variable_any>::value>()()
+              << "have native_handle.\n\n";
+
+    std::cout << "std::thread does "
+              << choose<has_native_handle_type<std::thread>::value>()()
+              << "have native_handle_type.\n";
+    std::cout << "std::thread does "
+              << choose<has_native_handle<std::thread>::value>()()
+              << "have native_handle.\n";
+}
+
+/*
+Output:
+
+Demonstration of automatic detection of native_handle_type and native_handle.
+For this implementation of the threading API:
+
+std::mutex does have native_handle_type.
+std::mutex does have native_handle.
+
+std::recursive_mutex does have native_handle_type.
+std::recursive_mutex does have native_handle.
+
+std::timed_mutex does not have native_handle_type.
+std::timed_mutex does not have native_handle.
+
+std::recursive_timed_mutex does not have native_handle_type.
+std::recursive_timed_mutex does not have native_handle.
+
+std::condition_variable does have native_handle_type.
+std::condition_variable does have native_handle.
+
+std::condition_variable_any does not have native_handle_type.
+std::condition_variable_any does not have native_handle.
+
+std::thread does have native_handle_type.
+std::thread does have native_handle.
+*/