?vout expects a vector, so make sure to pass a vector

[dschwoerer]

Pull request purpose

Make arpack compatible with gcc 10

Detailed changes proposed in this pull request

replacing scalar variables with vectors by enclosing [] around it, as described in the porting guide

With these fixes, arpack compiles and the tests run as well with gcc 10.

[coveralls]

Pull Request Test Coverage Report for Build 1091

• 12 of 12 (100.0%) changed or added relevant lines in 6 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.03%) to 73.218%

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Totals
Change from base Build 951:	0.03%
Covered Lines:	16466
Relevant Lines:	22489

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💛 - Coveralls

[sylvestre]

@fghoussen wdyt? thanks

[sylvestre]

@dschwoerer could you please also update the changelog? thanks!

[fghoussen]

@sylvestre : not aware of that.

@dschwoerer : could understand it's a necessary change (which must be done) but to me, first, it's necessary to check if :

• it does not break compilation with other compilers (icc/ifort/clang...) : did you check that ?

• you add 1 or 2 other build in CI dedicated to test :

  1. build with gcc-10 (apt-get install gcc-10)

  2. build with clang (apt-get clang flang)

[dschwoerer]

I tried icc/ifortran and make all check failed, but make ; make all; make check worked.

flang seems to be only for llvm 7, but fedora ships llvm 10. ubuntu:latest doesn't seem to have flang either (I tried apt-get update; apt-get install flang)

Will add an test with gcc-10, not sure how to do llvm ...

I noticed I only ported the serial version. The parallel isn't that hard to get compiling, but then some tests fail. As far as I understand [] creates a temporary array, which is fine for printing, but not for receiving (MPI) data. So that will need some more effort ...

[fghoussen]

@dschwoerer : for gcc-10 you likely could use debian folowwing example

arpack-ng/.travis.yml

Line 231 in 3dd2d5f

sudo docker create --name mobydick debian /bin/bash -c \

where I see gcc-10 packages (not tested). Fro flang/clang you may use debian another OS (ubuntu or whatever you are familiar with). Unfortunately, for icc/ifort/pgi not way to test with open-sourced CI...