Replace custom type traits with std one's

Remove most type traits from qtypetraits.h, but keep the custom
implementation of is_signed/is_unsigned. This gets rid of
BSD-3 licensed code from Google in a public header (hugh!).

The custom implementations for is_signed/is_unsigned are kept
because the implementations in gcc's standard headers do not
work as we expect for enums - both is_signed and is_unsigned
always returns false there - see also
  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59027

[ChangeLog][QtCore][General] Qt now relies on type traits from
the C++ standard library.

Change-Id: I3f2188b46949f04ca4482a6ac9afd3482103f0e1
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/src/corelib/tools/qstringalgorithms_p.h b/src/corelib/tools/qstringalgorithms_p.h
index d7127517e0..c5470bc7ad 100644
--- a/src/corelib/tools/qstringalgorithms_p.h
+++ b/src/corelib/tools/qstringalgorithms_p.h
@@ -60,8 +60,8 @@ template <typename StringType> struct QStringAlgorithms
 {
     typedef typename StringType::value_type Char;
     typedef typename StringType::size_type size_type;
-    typedef typename QtPrivate::remove_cv<StringType>::type NakedStringType;
-    static const bool isConst = QtPrivate::is_const<StringType>::value;
+    typedef typename std::remove_cv<StringType>::type NakedStringType;
+    static const bool isConst = std::is_const<StringType>::value;
 
     static inline bool isSpace(char ch) { return ascii_isspace(ch); }
     static inline bool isSpace(QChar ch) { return ch.isSpace(); }