I just tried building proj 5.2.0 on Linux with g++, and I got this:
>[ 37s] checking whether g++ supports C++11 features with -h std=c++11... no
>[ 37s] configure: error: *** A compiler with support for C++11
Shouldn't the test
-h std=c++1
be
-std=c++11
--
Roger Oberholtzer