Fix a few more clang analysis problems. (#731)

In particular, make sure to mark the fact that we are
C++17 (as the emplace_back signature changed), and also
add in a few more (void)_ for benchmark tests.

Signed-off-by: Chris Lalancette <clalancette@gmail.com>

rosidl_runtime_cpp/CMakeLists.txt

@@ -41,6 +41,7 @@ if(BUILD_TESTING)
   # Default to C++17
   if(NOT CMAKE_CXX_STANDARD)
     set(CMAKE_CXX_STANDARD 17)
+    set(CMAKE_CXX_STANDARD_REQUIRED ON)
   endif()
 
   if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")

rosidl_runtime_cpp/test/benchmark/benchmark_bounded_vector.cpp

@@ -33,6 +33,7 @@ BENCHMARK_F(PerformanceTest, bounded_vector)(benchmark::State & st)
   reset_heap_counters();
 
   for (auto _ : st) {
+    (void)_;
     v.push_back(0);
     v.erase(v.begin());
   }
@@ -47,6 +48,7 @@ BENCHMARK_F(PerformanceTest, bounded_vector_rvalue)(benchmark::State & st)
   reset_heap_counters();
 
   for (auto _ : st) {
+    (void)_;
     v.emplace_back(0);
     v.erase(v.begin());
   }
@@ -63,6 +65,7 @@ BENCHMARK_F(PerformanceTest, bounded_vector_insert)(benchmark::State & st)
   reset_heap_counters();
 
   for (auto _ : st) {
+    (void)_;
     v.insert(v.begin(), v2.begin(), v2.end());
     v.erase(v.begin());
   }
@@ -82,6 +85,7 @@ BENCHMARK_F(PerformanceTest, bounded_vector_input_iterators)(benchmark::State &
   reset_heap_counters();
 
   for (auto _ : st) {
+    (void)_;
     v.assign(ii, end);
     v.erase(v.begin());
   }
@@ -98,6 +102,7 @@ BENCHMARK_F(PerformanceTest, bounded_vector_forward_iterators)(benchmark::State
   reset_heap_counters();
 
   for (auto _ : st) {
+    (void)_;
     v.assign(l.begin(), l.end());
     v.erase(v.begin());
   }

rosidl_typesupport_introspection_tests/CMakeLists.txt

@@ -7,6 +7,11 @@ if(BUILD_TESTING)
   find_package(ament_lint_auto REQUIRED)
   ament_lint_auto_find_test_dependencies()
 
+  # Default to C++17
+  if(NOT CMAKE_CXX_STANDARD)
+    set(CMAKE_CXX_STANDARD 17)
+    set(CMAKE_CXX_STANDARD_REQUIRED ON)
+  endif()
   if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")
     add_compile_options(-Wall -Wextra -Wpedantic)
   endif()