added negation operator for FieldMatrix

4 jobs for issue/missing_fmatrix_operator in 20 minutes and 16 seconds (queued for 9 seconds)
Status Job ID Name Coverage
  Test
passed #7612
debian:10 clang-6-libcpp-17

00:20:15

passed #7611
debian:10 gcc-8-17

00:16:09

passed #7613
debian:9 gcc-6-14

00:13:41

passed #7614
ubuntu:18.04 clang-6-17

00:19:02