Installation error

[micdonato]

Hello,

I am trying to install uwot on our RStudio Server and I am getting an error I cannot decipher (google cannot do that either...).

In file included from gradient.cpp:20:
gradient.h:30: error: ISO C++ forbids declaration of ‘constexpr’ with no type
gradient.h:30: error: expected ‘;’ before ‘double’
gradient.h:56: error: ISO C++ forbids declaration of ‘constexpr’ with no type
gradient.h:56: error: expected ‘;’ before ‘double’
gradient.h:64: error: ISO C++ forbids declaration of ‘constexpr’ with no type
gradient.h:64: error: expected ‘;’ before ‘double’
make: *** [gradient.o] Error 1
ERROR: compilation failed for package ‘uwot’
* removing ‘/home/myuser/R/x86_64-pc-linux-gnu-library/3.5/uwot’
Error in i.p(...) : 
  (converted from warning) installation of package ‘/tmp/Rtmp9wtvCO/file2accb4660569f/uwot_0.0.0.9008.tar.gz’ had non-zero exit status

Any idea of what can cause this?

RStudio is running R 3.5.1, I installed RCpp and RCppParallel without any issue. We might have an old-ish version of GCC (4.4.7) , so that might be the issue, but I want to make sure before I go to war against our sysadmin.

[jlmelville]

From the look of things GCC 4.4 has only spotty support for C++11. Maybe adding -std=c++0x or -std=gnu++0x as a build flag will help, but the linked web page indicates that "generalized constant expressions" (constexpr) isn't supported. Upgrading may be your only option. Sorry.

[jlmelville]

Closing due to inactivity. @micdonato please reopen if you feel gcc 4.4 should work with the C++ code in uwot.