CHECK support for nullptr (fixes google#341)

This allows CHECK_NE(foo, nullptr) to compile and produces "nullptr" for the
string representation of nullptr.

CMakeLists.txt

@@ -240,6 +240,12 @@ std::atomic<int> i;
 int main() { }
 " HAVE_CXX11_ATOMIC)
 
+check_cxx_source_compiles ("
+#include <cstddef>
+void foo(std::nullptr_t) {}
+int main(void) { foo(nullptr); }
+" HAVE_CXX11_NULLPTR_T)
+
 if (WITH_TLS)
   # Cygwin does not support the thread attribute. Don't bother.
   if (HAVE_GCC_TLS)
@@ -381,6 +387,12 @@ else (HAVE_USING_OPERATOR)
   set (ac_cv_cxx_using_operator 0)
 endif (HAVE_USING_OPERATOR)
 
+if (HAVE_CXX11_NULLPTR_T)
+  set (ac_cv_cxx11_nullptr_t 1)
+else (HAVE_CXX11_NULLPTR_T)
+  set (ac_cv_cxx11_nullptr_t 0)
+endif (HAVE_CXX11_NULLPTR_T)
+
 if (HAVE_EXECINFO_H)
   set (HAVE_STACKTRACE 1)
 endif (HAVE_EXECINFO_H)

CONTRIBUTORS

@@ -26,6 +26,7 @@ Abhishek Dasgupta <abhi2743@gmail.com>
 Abhishek Parmar <abhishek@orng.net>
 Andrew Schwartzmeyer <andrew@schwartzmeyer.com>
 Andy Ying <andy@trailofbits.com>
+Bret McKee <bretmckee@google.com>
 Brian Silverman <bsilver16384@gmail.com>
 Fumitoshi Ukai <ukai@google.com>
 Guillaume Dumont <dumont.guillaume@gmail.com>

src/glog/logging.h.in

@@ -37,6 +37,7 @@
 #define _LOGGING_H_
 
 #include <cerrno>
+#include <cstddef>
 #include <cstring>
 #include <ctime>
 #include <iosfwd>
@@ -673,6 +674,13 @@ void MakeCheckOpValueString(std::ostream* os, const signed char& v);
 template <> GOOGLE_GLOG_DLL_DECL
 void MakeCheckOpValueString(std::ostream* os, const unsigned char& v);
 
+// This is required because nullptr is only present in c++ 11 and later.
+#if @ac_cv_cxx11_nullptr_t@
+// Provide printable value for nullptr_t
+template <> GOOGLE_GLOG_DLL_DECL
+void MakeCheckOpValueString(std::ostream* os, const std::nullptr_t& v);
+#endif
+
 // Build the error message string. Specify no inlining for code size.
 template <typename T1, typename T2>
 std::string* MakeCheckOpString(const T1& v1, const T2& v2, const char* exprtext)

src/logging.cc

@@ -2506,6 +2506,13 @@ void MakeCheckOpValueString(std::ostream* os, const unsigned char& v) {
   }
 }
 
+#if __cplusplus >= 201103L
+template <>
+void MakeCheckOpValueString(std::ostream* os, const std::nullptr_t& v) {
+  (*os) << "nullptr";
+}
+#endif
+
 void InitGoogleLogging(const char* argv0) {
   glog_internal_namespace_::InitGoogleLoggingUtilities(argv0);
 }