On 12/02/2023 01:33, Jonathan Wakely wrote: > > > On Sat, 11 Feb 2023, 23:38 Jonny Grant, <jg@xxxxxxxx <mailto:jg@xxxxxxxx>> wrote: > > Hello > > Anyone else seeing an issue when using c++23 ? > gcc (Ubuntu 12.2.0-3ubuntu1) 12.2.0 > > The only change is to use --std=c++23 > > > With C++17 std::string is instantiated in the library, not in your code. With C++20 your code instantiates it. That's the only reason the -std option matters here. Ok I see.