From 1d9dda3f09d164a6da66f37f622f51dd6c8b085c Mon Sep 17 00:00:00 2001
From: cudawarped <12133430+cudawarped@users.noreply.github.com>
Date: Fri, 21 Mar 2025 13:41:49 +0200
Subject: [PATCH] Merge pull request #27112 from cudawarped:add_cuda_c++17

cuda: Force C++17 Standard for CUDA targets when CUDA Toolkit >=12.8 #27112

Fix https://github.com/opencv/opencv/issues/27095.

### Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

- [x] I agree to contribute to the project under Apache 2 License.
- [x] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
- [ ] The PR is proposed to the proper branch
- [ ] There is a reference to the original bug report and related work
- [ ] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
      Patch to opencv_extra has the same branch name.
- [ ] The feature is well documented and sample code can be built with the project CMake
---
 cmake/OpenCVDetectCUDA.cmake         | 8 +++++---
 cmake/OpenCVDetectCUDALanguage.cmake | 6 ++++--
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/cmake/OpenCVDetectCUDA.cmake b/cmake/OpenCVDetectCUDA.cmake
index 06998400d7..c5ce8762f2 100644
--- a/cmake/OpenCVDetectCUDA.cmake
+++ b/cmake/OpenCVDetectCUDA.cmake
@@ -151,12 +151,14 @@ macro(ocv_cuda_compile VAR)
   ocv_check_windows_crt_linkage()
   ocv_nvcc_flags()
 
-  if(UNIX OR APPLE)
-    if(NOT " ${CMAKE_CXX_FLAGS} ${CMAKE_CXX_FLAGS_RELEASE} ${CMAKE_CXX_FLAGS_DEBUG} ${CUDA_NVCC_FLAGS}" MATCHES "-std=")
+  if(NOT " ${CMAKE_CXX_FLAGS} ${CMAKE_CXX_FLAGS_RELEASE} ${CMAKE_CXX_FLAGS_DEBUG} ${CUDA_NVCC_FLAGS}" MATCHES "-std=")
+    if(UNIX OR APPLE)
       if(CUDA_VERSION VERSION_LESS "11.0")
         list(APPEND CUDA_NVCC_FLAGS "--std=c++11")
-      else()
+      elseif(CUDA_VERSION VERSION_LESS "12.8")
         list(APPEND CUDA_NVCC_FLAGS "--std=c++14")
+      elseif(CUDA_VERSION VERSION_GREATER_EQUAL "12.8")
+        list(APPEND CUDA_NVCC_FLAGS "--std=c++17")
       endif()
     endif()
   endif()
diff --git a/cmake/OpenCVDetectCUDALanguage.cmake b/cmake/OpenCVDetectCUDALanguage.cmake
index 0eeea77f2c..bc40134180 100644
--- a/cmake/OpenCVDetectCUDALanguage.cmake
+++ b/cmake/OpenCVDetectCUDALanguage.cmake
@@ -33,10 +33,12 @@ if(CMAKE_CUDA_COMPILER AND CUDAToolkit_FOUND)
   set(CUDA_TOOLKIT_INCLUDE ${CUDAToolkit_INCLUDE_DIRS})
   set(CUDA_VERSION_STRING ${CUDAToolkit_VERSION})
   set(CUDA_VERSION ${CUDAToolkit_VERSION})
-  if(NOT CUDA_VERSION VERSION_LESS 11.0)
+  if(CUDA_VERSION VERSION_LESS 11.0)
+      set(CMAKE_CUDA_STANDARD 11)
+  elseif(CUDA_VERSION VERSION_LESS 12.8)
       set(CMAKE_CUDA_STANDARD 14)
   else()
-      set(CMAKE_CUDA_STANDARD 11)
+      set(CMAKE_CUDA_STANDARD 17)
   endif()
   if(UNIX AND NOT BUILD_SHARED_LIBS)
       set(CUDA_LIB_EXT "_static")