Path concat difference between std::filesystem and std::experimental::filesystem

Question

I was thinking to migrate from std::experimental::filesystem to std::filesystem , but my unit test started to break. I use Windows, VS2019 and MSVC compiler with /std:c++latest .

I narrowed the issue down to the difference between append methods (and operator/= ) from standard and experimental code bases.

#include <filesystem>
#include <experimental/filesystem>

int main() {
    std::filesystem::path p1 = "C:\\temp";
    p1 /= "\\test\\file.txt";           // Expected: C:\temp\test\file.txt, Actual C:\test\file.txt

    std::experimental::filesystem::path p2 = "C:\\temp";
    p2 /= "\\test\\file.txt";           // Expected: C:\temp\test\file.txt, Actual C:\temp\test\file.txt
}

Question : how can I use std::filesystem to append two path components on Windows to get C:\\temp\\test\\file.txt ?

Answer 1

当您附加绝对路径时，它会替换p1所有组件，您需要从\\\\test\\\\file.txt删除前导斜杠以使其成为相对路径，以便将其附加到p1 ：

p1 /= "test\\file.txt";