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.assign/source.pass.cpp

@@ -0,0 +1,153 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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& operator=(Source const&);
+// template <class Source>
+//      path& assign(Source const&);
+// template <class InputIterator>
+//      path& assign(InputIterator first, InputIterator last);
+
+
+#include <experimental/filesystem>
+#include <type_traits>
+#include <cassert>
+
+#include "test_macros.h"
+#include "test_iterators.h"
+#include "count_new.hpp"
+#include "filesystem_test_helper.hpp"
+#include <iostream>
+
+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);
+  //////////////////////////////////////////////////////////////////////////////
+  // basic_string<Char, Traits, Alloc>
+  {
+    const std::basic_string<CharT> S(TestPath);
+    path p; PathReserve(p, S.length() + 1);
+    {
+      // string provides a contigious iterator. No allocation needed.
+      DisableAllocationGuard g;
+      path& pref = (p = S);
+      assert(&pref == &p);
+    }
+    assert(p.native() == Expect);
+    assert(p.string<CharT>() == TestPath);
+    assert(p.string<CharT>() == S);
+  }
+  {
+    const std::basic_string<CharT> S(TestPath);
+    path p; PathReserve(p, S.length() + 1);
+    {
+      DisableAllocationGuard g;
+      path& pref = p.assign(S);
+      assert(&pref == &p);
+    }
+    assert(p.native() == Expect);
+    assert(p.string<CharT>() == TestPath);
+    assert(p.string<CharT>() == S);
+  }
+  //////////////////////////////////////////////////////////////////////////////
+  // Char* pointers
+  {
+    path p; PathReserve(p, Size + 1);
+    {
+      // char* pointers are contigious and can be used with code_cvt directly.
+      // no allocations needed.
+      DisableAllocationGuard g;
+      path& pref = (p = TestPath);
+      assert(&pref == &p);
+    }
+    assert(p.native() == Expect);
+    assert(p.string<CharT>() == TestPath);
+  }
+  {
+    path p; PathReserve(p, Size + 1);
+    {
+      DisableAllocationGuard g;
+      path& pref = p.assign(TestPath);
+      assert(&pref == &p);
+    }
+    assert(p.native() == Expect);
+    assert(p.string<CharT>() == TestPath);
+  }
+  {
+    path p; PathReserve(p, Size + 1);
+    {
+      DisableAllocationGuard g;
+      path& pref = p.assign(TestPath, TestPathEnd);
+      assert(&pref == &p);
+    }
+    assert(p.native() == Expect);
+    assert(p.string<CharT>() == TestPath);
+  }
+  //////////////////////////////////////////////////////////////////////////////
+  // Iterators
+  {
+    using It = input_iterator<const CharT*>;
+    path p; PathReserve(p, Size + 1);
+    It it(TestPath);
+    {
+      // Iterators cannot be used with code_cvt directly. This assignment
+      // may allocate if it's larger than a "short-string".
+      path& pref = (p = it);
+      assert(&pref == &p);
+    }
+    assert(p.native() == Expect);
+    assert(p.string<CharT>() == TestPath);
+  }
+  {
+    using It = input_iterator<const CharT*>;
+    path p; PathReserve(p, Size + 1);
+    It it(TestPath);
+    {
+      path& pref = p.assign(it);
+      assert(&pref == &p);
+    }
+    assert(p.native() == Expect);
+    assert(p.string<CharT>() == TestPath);
+  }
+  {
+    using It = input_iterator<const CharT*>;
+    path p; PathReserve(p, Size + 1);
+    It it(TestPath);
+    It e(TestPathEnd);
+    {
+      path& pref = p.assign(it, e);
+      assert(&pref == &p);
+    }
+    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);
+  }
+}