Index: include/istream
===================================================================
--- include/istream
+++ include/istream
@@ -695,6 +695,11 @@
     return *this;
 }
 
+#if __clang_major__ >= 6
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wtautological-constant-compare"
+#endif
+
 template <class _CharT, class _Traits>
 basic_istream<_CharT, _Traits>&
 basic_istream<_CharT, _Traits>::operator>>(int& __n)
@@ -735,6 +740,10 @@
     return *this;
 }
 
+#if __clang_major__ >= 6
+#pragma clang diagnostic pop
+#endif
+
 template<class _CharT, class _Traits>
 basic_istream<_CharT, _Traits>&
 operator>>(basic_istream<_CharT, _Traits>& __is, _CharT* __s)
Index: src/string.cpp
===================================================================
--- src/string.cpp
+++ src/string.cpp
@@ -80,6 +80,11 @@
 V
 as_integer(const string& func, const S& s, size_t* idx, int base);
 
+#if __clang_major__ >= 6
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wtautological-constant-compare"
+#endif
+
 // string
 template<>
 inline
@@ -93,6 +98,10 @@
     return static_cast<int>(r);
 }
 
+#if __clang_major__ >= 6
+#pragma clang diagnostic pop
+#endif
+
 template<>
 inline
 long
@@ -125,6 +134,11 @@
     return as_integer_helper<unsigned long long>( func, s, idx, base, strtoull );
 }
 
+#if __clang_major__ >= 6
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wtautological-constant-compare"
+#endif
+
 // wstring
 template<>
 inline
@@ -138,6 +152,10 @@
     return static_cast<int>(r);
 }
 
+#if __clang_major__ >= 6
+#pragma clang diagnostic pop
+#endif
+
 template<>
 inline
 long