some fixes

std::function is already nullptr by default. thus, there is no need to initialize its by by nullptr manually.

Author: EfesX

include/benchmark/benchmark.h

@@ -1162,8 +1162,6 @@ class BENCHMARK_EXPORT Benchmark {
   //
   // The callback will be passed a State object, which includes the number
   // of threads, thread-index, benchmark arguments, etc.
-  //
-  // The callback must not be NULL or self-deleting.
   Benchmark* Setup(callback_function&&);
   Benchmark* Setup(const callback_function&);
   Benchmark* Teardown(callback_function&&);

src/benchmark_api_internal.cc

@@ -27,7 +27,9 @@ BenchmarkInstance::BenchmarkInstance(Benchmark* benchmark, int family_idx,
       min_time_(benchmark_.min_time_),
       min_warmup_time_(benchmark_.min_warmup_time_),
       iterations_(benchmark_.iterations_),
-      threads_(thread_count) {
+      threads_(thread_count),
+      setup_(benchmark_.setup_),
+      teardown_(benchmark_.teardown_) {
   name_.function_name = benchmark_.name_;
 
   size_t arg_i = 0;
@@ -84,9 +86,6 @@ BenchmarkInstance::BenchmarkInstance(Benchmark* benchmark, int family_idx,
   if (!benchmark_.thread_counts_.empty()) {
     name_.threads = StrFormat("threads:%d", threads_);
   }
-
-  setup_ = benchmark_.setup_;
-  teardown_ = benchmark_.teardown_;
 }
 
 State BenchmarkInstance::Run(

src/benchmark_api_internal.h

@@ -68,8 +68,8 @@ class BenchmarkInstance {
   IterationCount iterations_;
   int threads_;  // Number of concurrent threads to us
 
-  callback_function setup_ = nullptr;
-  callback_function teardown_ = nullptr;
+  callback_function setup_;
+  callback_function teardown_;
 };
 
 bool FindBenchmarksInternal(const std::string& re,

src/benchmark_register.cc

@@ -224,9 +224,7 @@ Benchmark::Benchmark(const std::string& name)
       use_real_time_(false),
       use_manual_time_(false),
       complexity_(oNone),
-      complexity_lambda_(nullptr),
-      setup_(nullptr),
-      teardown_(nullptr) {
+      complexity_lambda_(nullptr) {
   ComputeStatistics("mean", StatisticsMean);
   ComputeStatistics("median", StatisticsMedian);
   ComputeStatistics("stddev", StatisticsStdDev);