third-party/benchmark/src/benchmark_name.cc

   1 // Copyright 2015 Google Inc. All rights reserved.
   2 //
   3 // Licensed under the Apache License, Version 2.0 (the "License");
   4 // you may not use this file except in compliance with the License.
   5 // You may obtain a copy of the License at
   6 //
   7 //     http://www.apache.org/licenses/LICENSE-2.0
   8 //
   9 // Unless required by applicable law or agreed to in writing, software
  10 // distributed under the License is distributed on an "AS IS" BASIS,
  11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 // See the License for the specific language governing permissions and
  13 // limitations under the License.
  14
  15 #include <benchmark/benchmark.h>
  16
  17 namespace benchmark {
  18
  19 namespace {
  20
  21 // Compute the total size of a pack of std::strings
  22 size_t size_impl() { return 0; }
  23
  24 template <typename Head, typename... Tail>
  25 size_t size_impl(const Head& head, const Tail&... tail) {
  26   return head.size() + size_impl(tail...);
  27 }
  28
  29 // Join a pack of std::strings using a delimiter
  30 // TODO: use absl::StrJoin
  31 void join_impl(std::string&, char) {}
  32
  33 template <typename Head, typename... Tail>
  34 void join_impl(std::string& s, const char delimiter, const Head& head,
  35                const Tail&... tail) {
  36   if (!s.empty() && !head.empty()) {
  37     s += delimiter;
  38   }
  39
  40   s += head;
  41
  42   join_impl(s, delimiter, tail...);
  43 }
  44
  45 template <typename... Ts>
  46 std::string join(char delimiter, const Ts&... ts) {
  47   std::string s;
  48   s.reserve(sizeof...(Ts) + size_impl(ts...));
  49   join_impl(s, delimiter, ts...);
  50   return s;
  51 }
  52 }  // namespace
  53
  54 std::string BenchmarkName::str() const {
  55   return join('/', function_name, args, min_time, iterations, repetitions,
  56               time_type, threads);
  57 }
  58 }  // namespace benchmark