On Mon, May 11, 2015 at 1:29 PM, Paul Smith <paul@xxxxxxxxxxxxxxxxx> wrote: > On Mon, 2015-05-11 at 12:40 -0400, Michael Powell wrote: >> > Imagine you write a library and you compile and distribute the >> > binaries. Someone else builds against those. If std::set is used in >> > your API, and they have a different version of libstdc++, do you still >> > want the library and the binary to be compatible, even across >> > different versions of libstdc++? >> >> Playing devil's advocate, I want interface compatibility. > > Indeed. But "interface" is part of both API and ABI so your statement > doesn't help answer the question. > > If you want to be able to link against pre-compiled libraries, then you > require *binary* interface compatibility. Making changes to the > underlying type of a std:: type can break the ABI. > > If you're OK with recompiling everything yourself rather than using > pre-compiled libraries, then you only require *program* interface > compatibility. In this case it's straightforward to make those changes. Thanks for clarifying the comparison/contrast. > Most people really require ABI stability for a library like libstdc++. >
