Make filesystem::path comparison operators hidden friends (LWG 3065)

This change revealed two testsuite bugs where some string comparisons
only compiled by converting the strings to filesystem::path objects.

	* include/bits/fs_path.h (operator<, operator<=, operator>)
	(operator>=, operator==, operator!=): Make hidden friends, as per
	LWG 3065.
	* testsuite/27_io/filesystem/path/native/string-char8_t.cc: Fix
	string type in test.
	* testsuite/27_io/filesystem/path/native/string.cc: Likewise.

From-SVN: r270558

libstdc++-v3/ChangeLog

 2019-04-24  Jonathan Wakely  <jwakely@redhat.com>
 
+	* include/bits/fs_path.h (operator<, operator<=, operator>)
+	(operator>=, operator==, operator!=): Make hidden friends, as per
+	LWG 3065.
+	* testsuite/27_io/filesystem/path/native/string-char8_t.cc: Fix
+	string type in test.
+	* testsuite/27_io/filesystem/path/native/string.cc: Likewise.
+
 	* include/std/any (any::any(ValueType&&)): Use __and_v.
 	* include/std/numeric (midpoint(T, T, T), midpoint(T*, T*, T*)):
 	Likewise.

libstdc++-v3/include/bits/fs_path.h

@@ -417,6 +417,40 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
 	return __is;
       }
 
+    // non-member operators
+
+    /// Compare paths
+    friend bool operator<(const path& __lhs, const path& __rhs) noexcept
+    { return __lhs.compare(__rhs) < 0; }
+
+    /// Compare paths
+    friend bool operator<=(const path& __lhs, const path& __rhs) noexcept
+    { return !(__rhs < __lhs); }
+
+    /// Compare paths
+    friend bool operator>(const path& __lhs, const path& __rhs) noexcept
+    { return __rhs < __lhs; }
+
+    /// Compare paths
+    friend bool operator>=(const path& __lhs, const path& __rhs) noexcept
+    { return !(__lhs < __rhs); }
+
+    /// Compare paths
+    friend bool operator==(const path& __lhs, const path& __rhs) noexcept
+    { return __lhs.compare(__rhs) == 0; }
+
+    /// Compare paths
+    friend bool operator!=(const path& __lhs, const path& __rhs) noexcept
+    { return !(__lhs == __rhs); }
+
+    /// Append one path to another
+    friend path operator/(const path& __lhs, const path& __rhs)
+    {
+      path __result(__lhs);
+      __result /= __rhs;
+      return __result;
+    }
+
     // Create a basic_string by reading until a null character.
     template<typename _InputIterator,
 	     typename _Traits = std::iterator_traits<_InputIterator>,
@@ -578,38 +612,6 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
 
   size_t hash_value(const path& __p) noexcept;
 
-  /// Compare paths
-  inline bool operator<(const path& __lhs, const path& __rhs) noexcept
-  { return __lhs.compare(__rhs) < 0; }
-
-  /// Compare paths
-  inline bool operator<=(const path& __lhs, const path& __rhs) noexcept
-  { return !(__rhs < __lhs); }
-
-  /// Compare paths
-  inline bool operator>(const path& __lhs, const path& __rhs) noexcept
-  { return __rhs < __lhs; }
-
-  /// Compare paths
-  inline bool operator>=(const path& __lhs, const path& __rhs) noexcept
-  { return !(__lhs < __rhs); }
-
-  /// Compare paths
-  inline bool operator==(const path& __lhs, const path& __rhs) noexcept
-  { return __lhs.compare(__rhs) == 0; }
-
-  /// Compare paths
-  inline bool operator!=(const path& __lhs, const path& __rhs) noexcept
-  { return !(__lhs == __rhs); }
-
-  /// Append one path to another
-  inline path operator/(const path& __lhs, const path& __rhs)
-  {
-    path __result(__lhs);
-    __result /= __rhs;
-    return __result;
-  }
-
   template<typename _InputIterator>
     inline auto
     u8path(_InputIterator __first, _InputIterator __last)

libstdc++-v3/testsuite/27_io/filesystem/path/native/string-char8_t.cc

@@ -46,7 +46,7 @@ test02()
   path p(s);
 
   auto str = p.string<char>();
-  VERIFY( str == u"abc" );
+  VERIFY( str == "abc" );
   VERIFY( str == p.string() );
 
   auto strw = p.string<wchar_t>();

libstdc++-v3/testsuite/27_io/filesystem/path/native/string.cc

@@ -46,7 +46,7 @@ test02()
   path p(s);
 
   auto str = p.string<char>();
-  VERIFY( str == u"abc" );
+  VERIFY( str == "abc" );
   VERIFY( str == p.string() );
 
   auto strw = p.string<wchar_t>();