C++20 support

Question

C++20 support

jhurliman opened this issue a year ago · comments

Description

../apps/websocket_node/foxglove_websocket/include/foxglove/websocket/websocket_server.hpp:266:37: error: aggregate initialization of type 'foxglove::Server<foxglove::WebSocketNoTls>::ClientInfo' with user-declared constructors is incompatible with C++20 [-Werror,-Wc++20-compat]
    _clients.emplace(hdl, ClientInfo{endpoint, hdl, {}, {}});
                                    ^~~~~~~~~~~~~~~~~~~~~~~

foxhubber · Answer 1 · Thu Mar 30 2023 06:33:12 GMT+0800 (China Standard Time)

Internal tracking ticket: FG-2707

Roman Shtylman · Answer 2 · Thu Mar 30 2023 06:39:57 GMT+0800 (China Standard Time)

Is the issue that we are doing something that requires newer C++ or we are doing something that is ok in older C++ but not ok in newer?

John Hurliman · Answer 3 · Thu Mar 30 2023 07:17:41 GMT+0800 (China Standard Time)

We are doing something that is ok in C++17 and earlier but (apparently) not allowed in C++20. The codebase I'm trying to integrate this library into builds as C++20.

John Hurliman · Answer 4 · Thu Mar 30 2023 07:20:32 GMT+0800 (China Standard Time)

There's a simple solution in this case, declare a new constructor:

ClientInfo(const std::string& name, ConnHandle handle)
        : name(name)
        , handle(handle) {}

And instantiate with ClientInfo{endpoint, hdl}

Roman Shtylman · Answer 5 · Thu Mar 30 2023 08:04:06 GMT+0800 (China Standard Time)

👍 Sounds good. I'm changing this to a feature request for c++20 - seems like we only support c++17 right now. I've thrown this into an upcoming work stream since it looks like an easy fix. We'll also update the README with the c++ version we believe is supported when we update to support c++20 so folks from the future don't get too many ideas.