Add Filesystem TS -- Complete

Add the completed std::experimental::filesystem implementation and tests.
The implementation supports C++11 or newer.

The TS is built as part of 'libc++experimental.a'. Users of the TS need to
manually link this library. Building and testing the TS can be disabled using
the CMake option '-DLIBCXX_ENABLE_FILESYSTEM=OFF'.

Currently 'libc++experimental.a' is not installed by default. To turn on the
installation of the library use '-DLIBCXX_INSTALL_EXPERIMENTAL_LIBRARY=ON'.


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@273034 91177308-0d34-0410-b5e6-96231b3b80d8

test/std/experimental/filesystem/class.path/path.member/path.construct/source.pass.cpp

@@ -0,0 +1,83 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03
+
+// <experimental/filesystem>
+
+// class path
+
+// template <class Source>
+//      path(const Source& source);
+// template <class InputIterator>
+//      path(InputIterator first, InputIterator last);
+
+
+#include <experimental/filesystem>
+#include <type_traits>
+#include <cassert>
+
+#include "test_macros.h"
+#include "test_iterators.h"
+#include "min_allocator.h"
+#include "filesystem_test_helper.hpp"
+
+namespace fs = std::experimental::filesystem;
+
+template <class CharT>
+void RunTestCase(MultiStringType const& MS) {
+  using namespace fs;
+  const char* Expect = MS;
+  const CharT* TestPath = MS;
+  const CharT* TestPathEnd = StrEnd(TestPath);
+  const std::size_t Size = TestPathEnd - TestPath;
+  const std::size_t SSize = StrEnd(Expect) - Expect;
+  assert(Size == SSize);
+  // StringTypes
+  {
+    const std::basic_string<CharT> S(TestPath);
+    path p(S);
+    assert(p.native() == Expect);
+    assert(p.string<CharT>() == TestPath);
+    assert(p.string<CharT>() == S);
+  }
+  // Char* pointers
+  {
+    path p(TestPath);
+    assert(p.native() == Expect);
+    assert(p.string<CharT>() == TestPath);
+  }
+  {
+    path p(TestPath, TestPathEnd);
+    assert(p.native() == Expect);
+    assert(p.string<CharT>() == TestPath);
+  }
+  // Iterators
+  {
+    using It = input_iterator<const CharT*>;
+    path p(It{TestPath});
+    assert(p.native() == Expect);
+    assert(p.string<CharT>() == TestPath);
+  }
+  {
+    using It = input_iterator<const CharT*>;
+    path p(It{TestPath}, It{TestPathEnd});
+    assert(p.native() == Expect);
+    assert(p.string<CharT>() == TestPath);
+  }
+}
+
+int main() {
+  for (auto const& MS : PathList) {
+    RunTestCase<char>(MS);
+    RunTestCase<wchar_t>(MS);
+    RunTestCase<char16_t>(MS);
+    RunTestCase<char32_t>(MS);
+  }
+}