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Compilation issue in ComplexQZ.h: 'steps' set but not used

Summary

When compiling git head (d426838d) using a recent clang and -Wall, I get the following errors:

Eigen/src/Eigenvalues/ComplexQZ.h:272:7: error: variable 'steps' set but not used [-Werror,-Wunused-but-set-variable]

  272 |   int steps = 0;

/Users/russ/tools/eigen-latest/Eigen/src/Eigenvalues/ComplexQZ.h:334:16: error: variable 'steps' set but not used [-Werror,-Wunused-but-set-variable]

  334 |   unsigned int steps = 0;

The compiler is correct in this case - the variable 'steps' is set but never used in two places. Possible solutions are to remove it, or if it's going to be useful later, add [[maybe_unused]].

Environment

  • Operating System : MacOS
  • Architecture : Arm64
  • Eigen Version : head
  • Compiler Version : clang version 21.0.0git
  • Compile Flags : -Werror -Wall -std=c++20