How to do out-of-source build?

[mloskot]

TL;TR: How to perform out-of-source build of Boost?

The documentation about --build-dir says:

The option is primarily useful when building from read-only media.

This is quite clear, but what about the bootstrap part?

Let's say I unpacked boost_1_77_0.7z into C:\boost_1_77_0 and I want to keep the directory completely clean as it was read-only,

How to build Boost in such way that everything generated goes to separate C:\boost_1_77_0_build ?
How to mimic cmake -S C:\boost_1_77_0 -B C:\boost_1_77_0_build?

[grisumbras]

1. Build b2 separately
2. Create a project-config manually
3. Point b2 to that file via --project-config

Essentially, don't run bootstrap.sh

It still might not help you, if some script creates in-source files anyway.

[mloskot]

Thanks, but not quite what I was looking for.

I think I will stick to the pattern I currently use:

1. Unpack
2. Copy to build directory
3. Enter the build directory, boostrap and build in there.

My goal was to avoid the step 2.