// Ceres Solver - A fast non-linear least squares minimizer
// Copyright 2020 Google Inc. All rights reserved.
// http://ceres-solver.org/
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// Author: darius.rueckert@fau.de (Darius Rueckert)
//
//
#ifndef CERES_INTERNAL_AUTODIFF_BENCHMARKS_CONSTANT_COST_FUNCTIONS_H_
#define CERES_INTERNAL_AUTODIFF_BENCHMARKS_CONSTANT_COST_FUNCTIONS_H_

#include "ceres/sized_cost_function.h"

namespace ceres {

template <int kParameterBlockSize>
struct ConstantCostFunction
    : public ceres::SizedCostFunction<1, kParameterBlockSize> {
  template <typename T>
  inline bool operator()(const T* const x, T* residuals) const {
    residuals[0] = T(5);
    return true;
  }

  virtual bool Evaluate(double const* const* parameters,
                        double* residuals,
                        double** jacobians) const {
    residuals[0] = 5.0;
    if (jacobians) {
      if (jacobians[0]) {
        memset(jacobians[0], 0, sizeof(double) * kParameterBlockSize);
      }
    }
    return true;
  }
};

}  // namespace ceres

#endif  // CERES_INTERNAL_AUTODIFF_BENCHMARKS_CONSTANT_COST_FUNCTIONS_H_