Compiler floor: C++20.
- Debian 13 (trixie) GCC 14.2: full support out of the box.
- RHEL 9 stock GCC 11: requires
gcc-toolset-14or newer (Red Hat-supported overlay; documented as the supported path). - RHEL 10 stock GCC 14: full support.
- FreeBSD 14.x base Clang 18+: full support.
- macOS Homebrew GCC 15+ / current Apple Clang: full support.
- vcpkg / Conan baseline: GCC 13+ / Clang 16+.
C++23 features used internally only: std::print, std::expected (when available) may appear in .cpp files behind feature-test macros, never in installed headers.
Autoconf: retained from v1. SOVERSION bumps from 1 to 2. New --disable-* flags follow existing conventions.
Distribution: distros package libhttpserver2 (binary) + libhttpserver2-dev / -devel (headers). Parallel-installable with libhttpserver1.