On Tue, 26 May 2026, 03:51 Adrian Johnston via Std-Proposals, <
std-proposals_at_[hidden]> wrote:

> *>> When you say "module build", what does this mean?*
>
> There are module source files provided by your compiler vendor for
> building the C++ standard library. For example:
>
> GNU std module: /usr/include/c++/15/bits/std.cc
> LLVM std module: /usr/lib/llvm-20/share/libc++/v1/std.cppm
>
> *>> Also, what "submodule support" are you referring to? The C++ standard
> doesn't have any submodules; there*
> *>> are just `std` and `std.compat`. *
>
> I was referring to the submodule support that does not exist.
>
> *>> And looking at those module use numbers, they seem pretty reasonable; **GCC
> could use some improvement,*
> *>> but the rest are at least an order of magnitude better than includes.*
>
> You are likely reading this email on a web browser that has over 30,000
> C++ files. If you were to try compiling that web browser with an ideal 50ms
> per-file taken to import the standard library? That is an additional 25
> minutes spent executing the single line* import std;* over and over again.
>

Nobody builds a web browser on one core, one file at a time though.


> And if you play video games, the time taken to call* import std;* on my
> laptop is also enough time to simulate a complex 3D world and render it to
> a 3840x2160 screen twice.
>

OK. But what's the alternative? What meaningful measurement are you
comparing it to? Drawing a frame to the screen isn't going to help you
build your program.

Don't things takes time.