Allow benchmarks to take arbitrary arguments. (#221)
* Add lambda benchmarks
* Remove lambda capture since the lambda is not at a block scope
* Remove LambdaBenchmark helper since FunctionBenchmark can be used with non-capturing lambas
* Add lambda benchmarks
* Remove lambda capture since the lambda is not at a block scope
* Remove LambdaBenchmark helper since FunctionBenchmark can be used with non-capturing lambas
* Add more docs for BENCHMARK_CAPTURE.
* Fix use of misnamed parameter
* Guard BENCHMARK_CAPTURE tests against non-c++11 compilers
* Move tests out of basic_test.cc
diff --git a/README.md b/README.md
index 377fe10..5be5153 100644
--- a/README.md
+++ b/README.md
@@ -176,6 +176,26 @@
#define BENCHMARK_TEMPLATE2(func, arg1, arg2)
```
+## Passing arbitrary arguments to a benchmark
+In C++11 it is possible to define a benchmark that takes an arbitrary number
+of extra arguments. The `BENCHMARK_CAPTURE(func, test_case_name, ...args)`
+macro creates a benchmark that invokes `func` with the `benchmark::State` as
+the first argument followed by the specified `args...`.
+The `test_case_name` is appended to the name of the benchmark and
+should describe the values passed.
+
+```c++
+template <class ...ExtraArgs>`
+void BM_takes_args(benchmark::State& state, ExtraArgs&&... extra_args) {
+ [...]
+}
+// Registers a benchmark named "BM_takes_args/int_string_test` that passes
+// the specified values to `extra_args`.
+BENCHMARK_CAPTURE(BM_takes_args, int_string_test, 42, std::string("abc"));
+```
+Note that elements of `...args` may refer to global variables. Users should
+avoid modifying global state inside of a benchmark.
+
### Multithreaded benchmarks
In a multithreaded test (benchmark invoked by multiple threads simultaneously),
it is guaranteed that none of the threads will start until all have called
diff --git a/include/benchmark/benchmark_api.h b/include/benchmark/benchmark_api.h
index 9f3be61..e705d75 100644
--- a/include/benchmark/benchmark_api.h
+++ b/include/benchmark/benchmark_api.h
@@ -650,6 +650,28 @@
#define BENCHMARK_RANGE2(n, l1, h1, l2, h2) \
BENCHMARK(n)->RangePair((l1), (h1), (l2), (h2))
+#if __cplusplus >= 201103L
+
+// Register a benchmark which invokes the function specified by `func`
+// with the additional arguments specified by `...`.
+//
+// For example:
+//
+// template <class ...ExtraArgs>`
+// void BM_takes_args(benchmark::State& state, ExtraArgs&&... extra_args) {
+// [...]
+//}
+// /* Registers a benchmark named "BM_takes_args/int_string_test` */
+// BENCHMARK_CAPTURE(BM_takes_args, int_string_test, 42, std::string("abc"));
+#define BENCHMARK_CAPTURE(func, test_case_name, ...) \
+ BENCHMARK_PRIVATE_DECLARE(func) = \
+ (::benchmark::internal::RegisterBenchmarkInternal( \
+ new ::benchmark::internal::FunctionBenchmark( \
+ #func "/" #test_case_name, \
+ [](::benchmark::State& st) { func(st, __VA_ARGS__); })))
+
+#endif // __cplusplus >= 11
+
// This will register a benchmark for a templatized function. For example:
//
// template<int arg>
diff --git a/test/benchmark_test.cc b/test/benchmark_test.cc
index 252602a..66f5956 100644
--- a/test/benchmark_test.cc
+++ b/test/benchmark_test.cc
@@ -16,6 +16,7 @@
#include <vector>
#include <chrono>
#include <thread>
+#include <utility>
#if defined(__GNUC__)
# define BENCHMARK_NOINLINE __attribute__((noinline))
@@ -202,5 +203,22 @@
BENCHMARK(BM_ManualTiming)->Range(1, 1 << 14)->UseRealTime();
BENCHMARK(BM_ManualTiming)->Range(1, 1 << 14)->UseManualTime();
+#if __cplusplus >= 201103L
+
+template <class ...Args>
+void BM_with_args(benchmark::State& state, Args&&...) {
+ while (state.KeepRunning()) {}
+}
+BENCHMARK_CAPTURE(BM_with_args, int_test, 42, 43, 44);
+BENCHMARK_CAPTURE(BM_with_args, string_and_pair_test,
+ std::string("abc"), std::pair<int, double>(42, 3.8));
+
+void BM_non_template_args(benchmark::State& state, int, double) {
+ while(state.KeepRunning()) {}
+}
+BENCHMARK_CAPTURE(BM_non_template_args, basic_test, 0, 0);
+
+#endif // __cplusplus >= 201103L
+
BENCHMARK_MAIN()
