Enable zero as NULL warnings and fix all occurences

CMakeLists.txt

@@ -38,8 +38,7 @@ add_cxx_compiler_flag(-Wextra)
 add_cxx_compiler_flag(-Wshadow)
 add_cxx_compiler_flag(-Werror)
 add_cxx_compiler_flag(-pedantic-errors)
-# TODO(ericwf): enable this for g++
-#add_cxx_compiler_flag(-Wzero-as-null-pointer-constant)
+add_cxx_compiler_flag(-Wzero-as-null-pointer-constant)
 # Release flags
 add_cxx_compiler_flag(-fno-strict-aliasing RELEASE)
 

include/benchmark/benchmark.h

@@ -152,7 +152,8 @@ void Initialize(int* argc, const char** argv);
 
 // Otherwise, run all benchmarks specified by the --benchmark_filter flag,
 // and exit after running the benchmarks.
-void RunSpecifiedBenchmarks(const BenchmarkReporter* reporter = NULL);
+void RunSpecifiedBenchmarks();
+void RunSpecifiedBenchmarks(const BenchmarkReporter* reporter);
 
 // If this routine is called, peak memory allocation past this point in the
 // benchmark is reported at the end of the benchmark report line. (It is
@@ -164,6 +165,19 @@ void RunSpecifiedBenchmarks(const BenchmarkReporter* reporter = NULL);
 namespace internal {
 class Benchmark;
 class BenchmarkFamilies;
+
+template <class T> struct Voider {
+    typedef void type;
+};
+
+template <class T, class = void>
+struct EnableIfString {};
+
+template <class T>
+struct EnableIfString<T, typename Voider<typename T::basic_string>::type> {
+    typedef int type;
+};
+
 }
 
 // State is passed to a running Benchmark and contains state for the
@@ -279,7 +293,7 @@ public:
   // as an injected class name in the case of std::string.
   template <class StringType>
   void SetLabel(StringType const & str,
-                typename StringType::basic_string* = 0) {
+                typename internal::EnableIfString<StringType>::type = 1) {
     this->SetLabel(str.c_str());
   }
 

src/benchmark.cc

@@ -898,6 +898,9 @@ void RunMatchingBenchmarks(const std::string& spec,
 
 } // end namespace internal
 
+void RunSpecifiedBenchmarks() {
+  RunSpecifiedBenchmarks(nullptr);
+}
 
 void RunSpecifiedBenchmarks(const BenchmarkReporter* reporter) {
   std::string spec = FLAGS_benchmark_filter;

src/sysinfo.cc

@@ -303,7 +303,7 @@ static bool MyCPUUsageCPUTimeNsLocked(double* cputime) {
     cputime_fd = -1;
     return false;
   }
-  unsigned long long result = strtoull(buff, NULL, 0);
+  unsigned long long result = strtoull(buff, nullptr, 0);
   if (result == (std::numeric_limits<unsigned long long>::max)()) {
     close(cputime_fd);
     cputime_fd = -1;

src/walltime.cc

@@ -89,7 +89,7 @@ private:
 
   WallTime Slow() const {
     struct timeval tv;
-    gettimeofday(&tv, NULL);
+    gettimeofday(&tv, nullptr);
     return tv.tv_sec + tv.tv_usec * 1e-6;
   }