C++17 Temporary Materialization Efficiency

[TheToaster]

I ran the following test on Godbolt:
https://godbolt.org/z/WtNfn7

As you can see, the C++17 compiled version is 319 lines of assembly, while the C++14/C++11 compiled version is only 46 lines. Why is that?

[dutch]

Maybe it's better code for debuggin?
Try compiling with -O1 instead of -O0

[TheToaster]

Ah yeah, that reduced the size of both to 19 lines