Update to C++17 minimum requirement.

Plus small changes to make compiler happy.

Signed-off-by: Henner Zeller <hzeller@google.com>

Author: hzeller

CMakeLists.txt

@@ -89,9 +89,9 @@ add_definitions("-DVTR_ASSERT_LEVEL=${VTR_ASSERT_LEVEL}")
 include(CheckCXXCompilerFlag)
 
 #
-# We require c++14 support
+# We require c++17 support
 #
-set(CMAKE_CXX_STANDARD 14)
+set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF) #No compiler specific extensions
 

vpr/src/route/rr_graph.cpp

@@ -1583,8 +1583,7 @@ static std::function<void(t_chan_width*)> alloc_and_load_rr_graph(RRGraphBuilder
     }
     VTR_LOG("CHAN->CHAN type edge count:%d\n", num_edges);
     num_edges = 0;
-    std::function<void(t_chan_width*)> update_chan_width = [](t_chan_width*) {
-    };
+    std::function<void(t_chan_width*)> update_chan_width = [](t_chan_width*) noexcept {};
     if (clock_modeling == DEDICATED_NETWORK) {
         ClockRRGraphBuilder builder(chan_width, grid, &L_rr_node, &rr_graph_builder);
         builder.create_and_append_clock_rr_graph(num_seg_types_x, &rr_edges_to_create);