conflict between math.h and cmath

[talismanbrandi]

bat/src/BCMath.cxx

Line 21 in f919caf

#include <math.h>

Hi,

TMath.h contains an inclusion of cmath. Including math.h after including TMath.h seems unnecessary. Also, it creates an error with some compilers, e.g. GCC 7.3.0.

In file included from BCMath.cxx:21:0:
/Users/ayanpaul/opt/local/include/c++/7.3.0/math.h:66:12: error: ‘constexpr bool std::isnan(double)’ conflicts with a previous declaration
using std::isnan;
^~~~~
In file included from BCMath.cxx:17:0:
/Users/ayanpaul/opt/local/include/TMath.h:407:19: note: previous declaration ‘int isnan(double)’
extern int isnan(double);

The code compiles just fine without the inclusion of math.h.

thanks!
Ayan

[oschulz]

Thanks for reporting this! We should indeed #include <cmath>. It should be included explicitly though, we shouldn't rely on indirect includes.

[talismanbrandi]

Thanks for looking into this. Including cmath indeed solves the problem the way you want to.

[fredRos]

@oschulz Would be great to use g++7.3 in our automated testing to really make sure this problem is fixed. Who can open a PR for the fix itself?

[fredRos]

I guess we can update our ubuntu container to use the latest g++ like this

GCC 8.1.0 on Ubuntu 14.04 & 16.04 & 18.04:

sudo apt-get update -y &&
sudo apt-get upgrade -y &&
sudo apt-get dist-upgrade -y &&
sudo apt-get install build-essential software-properties-common -y &&
sudo add-apt-repository ppa:ubuntu-toolchain-r/test -y &&
sudo apt-get update -y &&
sudo apt-get install gcc-8 g++-8 -y &&
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-8 60 --slave /usr/bin/g++ g++ /usr/bin/g++-8 &&
sudo update-alternatives --config gcc

select gcc-8

from https://gist.github.com/application2000/73fd6f4bf1be6600a2cf9f56315a2d91

[oschulz]

Closed by #321