Conan does not use parent project c++ standard version

The problem triggers on windows because mingw c++ standard is 14 there, but I think the issue is common to other platforms also.

Having qt creator and conan 2.0.6 installed.

Create a sample console project, create conanfile.txt at project root. Add following content:

[requires]
zxing-cpp/1.4.0 

Experience a failure on qt creator log message: conan uses standard c+14 while ZXing require c+17.

Check that project CMakeLists.txt uses c++17. (it was already the case for me)

Be sad

Solution for me was:

Move set(CMAKE_CXX_STANDARD 17) before project() call.

Add following lines in build-folder/.qtc/auto-setup.cmake at line 80:

    if (CMAKE_CXX_STANDARD)
      file(APPEND "${CMAKE_BINARY_DIR}/conan-dependencies/toolchain.cmake"
        "set(CMAKE_CXX_STANDARD \"${CMAKE_CXX_STANDARD}\")\n")
    endif() 

Re-run cmake, enjoy conan with c++17 support

But, solutions feels pretty dirty.