Missing path operator+=(path p) in 1.78

[achow101]

I recently updated to boost 1.78 and a project which uses boost::filesystem no longer compiles, emitting the error:

error: no match for ‘operator+=’ (operand types are ‘fs::path’ and ‘std::remove_reference<fs::path&>::type’ {aka ‘fs::path’})

It seems to be that path& operator+=(const path& p); is missing from filesystem/path.hpp in 1.78 (as it exists in previous versions), although the documentation states that this function still exists.

If I change to using concat(p), it works, but path& concat(const path& p); is not available in older versions of boost.

[Lastique]

The path argument is accepted by this operator+=. Please provide a small compilable repro.

[achow101]

It seems like the issue occurs when something subclasses boost::filesystem::path. https://github.com/achow101/super-carnival exhibits this failure.

[Lastique]

Thanks for the report.

BTW, you can work around this by explicitly casting the argument to boost::filesystem::path.