I ran some more measurements using import std; with a properly built module that includes reflection. I first created the module via: g++ -std=c++26 -fmodul

I ran some more measurements using import std; with a properly built module that includes reflection. I first created the module via: g++ -std=c++26 -fmodules -freflection -fsearch-include-path -fmodule-only -c bits/std.cc And then benchmarked with: hyperfine "g++ -std=c++26 -fmodules -freflection ./main.cpp" The only "include" was import std;, nothing else. These are the results: - Basic struct reflection: 352.8 ms - Barry's AoS -> SoA example: 1.077 s Compare that with PCH: - Basic struct reflection: 208.7 ms - Barry's AoS -> SoA example: 1.261 s So PCH actually wins for just <meta>, and modules are not that much better than PCH for the larger example. Very disappointing.