Add correct return type deduction for norm operations (#38)

12 jobs for master in 23 minutes and 5 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Static Test
passed #832146
linux elsa clang
clang-format

00:00:16

passed #832147
linux elsa clang
clang-tidy

00:00:24

 
  Compile
passed #832150
linux elsa clang
build-clang8

00:00:20

passed #832151
linux elsa gcc cuda
build-cuda92

00:00:25

passed #832149
linux elsa gcc
build-gcc9

00:00:21

passed #832148
linux elsa
build-ubuntu

00:00:21

 
  Test
passed #832154
linux elsa clang
test-clang8

00:03:38

passed #832155
linux elsa gcc cuda
test-cuda92

00:03:52

passed #832153
linux elsa gcc
test-gcc9

00:03:51

passed #832152
linux elsa
test-ubuntu

00:03:39

 
  Coverage
passed #832156
linux elsa gcc cuda
test-coverage

00:17:57

97.0%
 
  Docs
passed #832157
elsa-docs-deploy
deploy-docs

00:00:23