• Type: Correctness / API safety
• Severity: Medium
• Component: Pure-SoA particle container/type contracts
• Location:
  • Src/Particle/AMReX_ParticleContainer.H:1562
  • Src/Particle/AMReX_ParticleTile.H:432

Problem

ParticleContainerPureSoA<T_NArrayReal,...> allows any T_NArrayReal, but pure-SoA code assumes the first AMREX_SPACEDIM real components are particle positions (e.g., \ SoAParticle::pos() directly indexes m_rdata[0..AMREX_SPACEDIM-1]).

There is no compile-time guard enforcing T_NArrayReal >= AMREX_SPACEDIM.

Impact

• Invalid template instantiations compile but can perform out-of-bounds accesses at runtime.
• Failure mode is silent UB rather than a clear compile-time error.

Suggested patch

Add a compile-time contract for pure-SoA instantiations.

--- a/Src/Particle/AMReX_ParticleContainer.H
+++ b/Src/Particle/AMReX_ParticleContainer.H
@@
 class ParticleContainer_impl : public ParticleContainerBase
 {
 public:
@@
+    static_assert(!ParticleType::is_soa_particle || T_NArrayReal >= AMREX_SPACEDIM,
+                  "Pure SoA particle containers require at least AMREX_SPACEDIM real components for positions");

(Equivalent static_assert in SoAParticle<T_NArrayReal,...> is also acceptable.)

Prepared by Codex