Fixing GCC False-Positive Warnings in Eigen: A Deep Dive into -Warray-bounds at -O3

How a GCC 13 false-positive -Warray-bounds warning in Eigen’s TensorContraction led to a lesson about if constexpr, C++14 portability, and the right way to suppress compiler warnings in a large codebase.

March 18, 2026 · 4 min · Pavel Guzenfeld