From 60a229ef43e992702512c44c5b427a5b473be60b Mon Sep 17 00:00:00 2001
From: Fangjun Kuang <csukuangfj@gmail.com>
Date: Mon, 9 Oct 2023 18:28:02 +0800
Subject: [PATCH] Use C++17

---
 CMakeLists.txt    | 2 +-
 cmake/torch.cmake | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7808bd33e..b118d8c81 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -198,7 +198,7 @@ endif()
 
 # ========= Settings for CUB begin =========
 # the following settings are modified from cub/CMakeLists.txt
-set(CMAKE_CXX_STANDARD 14 CACHE STRING "The C++ version to be used.")
+set(CMAKE_CXX_STANDARD 14)
 set(CMAKE_CXX_EXTENSIONS OFF)
 
 message(STATUS "C++ Standard version: ${CMAKE_CXX_STANDARD}")
diff --git a/cmake/torch.cmake b/cmake/torch.cmake
index 8a6b2957f..c9ce268fc 100644
--- a/cmake/torch.cmake
+++ b/cmake/torch.cmake
@@ -56,6 +56,10 @@ execute_process(
 
 message(STATUS "PyTorch version: ${TORCH_VERSION}")
 
+if(TORCH_VERSION VERSION_GREATER_EQUAL "2.1")
+  set(CMAKE_CXX_STANDARD 17)
+endif()
+
 if(K2_WITH_CUDA)
 
   execute_process(