ACTS v37.3.0 "-Wmissing-template-arg-list-after-template-kw" issue with clang 19.1.2

[elmsheus]

Hi,

I am testing a build of AthenaExternals/Athena with clang 19.1.2 that contains ACTS v37.3.0 and run into the following compilation issue:

[..]
In file included from /build1/elmsheus/clang19_20241112/build/build/AthenaExternals/src/Acts/Core/src/TrackFitting/GlobalChiSquareFitter.cpp:9:
/build1/elmsheus/clang19_20241112/build/build/AthenaExternals/src/Acts/Core/include/Acts/TrackFitting/GlobalChiSquareFitter.hpp:1206:54: error: a template argument li
st is expected after a name prefixed by the template keyword [-Wmissing-template-arg-list-after-template-kw]
 1206 |       auto propagationResult = m_propagator.template propagate(propagatorState);
      |                                                      ^
/build1/elmsheus/clang19_20241112/build/build/AthenaExternals/src/Acts/Core/include/Acts/TrackFitting/GlobalChiSquareFitter.hpp:1209:43: error: a template argument list is expected after a name prefixed by the template keyword [-Wmissing-template-arg-list-after-template-kw]
 1209 |       auto result = m_propagator.template makeResult(std::move(propagatorState),
      |                                           ^
  CXX    dtrace-probe.o
[ 26%] Building CXX object source/processes/CMakeFiles/G4processes-static.dir/biasing/generic/src/G4InteractionLawPhysical.cc.o
/build1/elmsheus/clang19_20241112/build/build/AthenaExternals/src/Acts/Core/include/Acts/TrackFitting/GlobalChiSquareFitter.hpp:1448:54: error: a template argument list is expected after a name prefixed by the template keyword [-Wmissing-template-arg-list-after-template-kw]
 1448 |       auto propagationResult = m_propagator.template propagate(propagatorState);
      |                                                      ^
/build1/elmsheus/clang19_20241112/build/build/AthenaExternals/src/Acts/Core/include/Acts/TrackFitting/GlobalChiSquareFitter.hpp:1451:43: error: a template argument list is expected after a name prefixed by the template keyword [-Wmissing-template-arg-list-after-template-kw]
 1451 |       auto result = m_propagator.template makeResult(std::move(propagatorState),
      |                                           ^
[..]

The -Wmissing-template-arg-list-after-template-kw error is a known new feature of clang 19.1.* and several other external packages run into similar issues.

I've applied the following local patch to get ACTS compiling again, but there might be better code updates:

diff origin/acts-37.3.0/Core/include/Acts/TrackFitting/GlobalChiSquareFitter.hpp acts-37.3.0/Core/include/Acts/TrackFitting/GlobalChiSquareFitter.hpp 
1206c1206
<       auto propagationResult = m_propagator.template propagate(propagatorState);
---
>       auto propagationResult = m_propagator.template propagate<>(propagatorState);
1209c1209
<       auto result = m_propagator.template makeResult(std::move(propagatorState),
---
>       auto result = m_propagator.template makeResult<>(std::move(propagatorState),
1448c1448
<       auto propagationResult = m_propagator.template propagate(propagatorState);
---
>       auto propagationResult = m_propagator.template propagate<>(propagatorState);
1451c1451
<       auto result = m_propagator.template makeResult(std::move(propagatorState),
---
>       auto result = m_propagator.template makeResult<>(std::move(propagatorState),

Hope that's useful.
Cheers, Johannes

[AJPfleger]

Hi Johannes,

thanks for reporting the problem. I think that problem will be solved with:

• fix: oneAPI 2025 Fixes, main branch (2024.11.11.) #3846