Fix missing trailing return type in `__when_all_impl::__get_env` - #2237

maartenarnst wants to merge 1 commit into

Fix missing trailing return type in `__when_all_impl::__get_env`#2237
maartenarnst wants to merge 1 commit into
NVIDIA:mainfrom
uliegecsm:fix_when_all_get_env_type

Add trailing return type to when_all get_env