MYNT-EYE-S-SDK/3rdparty/ceres-solver-1.11.0/include/ceres/cost_function_to_functor.h
2019-01-03 16:25:18 +08:00

683 lines
21 KiB
C++

// Ceres Solver - A fast non-linear least squares minimizer
// Copyright 2015 Google Inc. All rights reserved.
// http://ceres-solver.org/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
// * Neither the name of Google Inc. nor the names of its contributors may be
// used to endorse or promote products derived from this software without
// specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
// Author: sameeragarwal@google.com (Sameer Agarwal)
//
// CostFunctionToFunctor is an adapter class that allows users to use
// SizedCostFunction objects in templated functors which are to be used for
// automatic differentiation. This allows the user to seamlessly mix
// analytic, numeric and automatic differentiation.
//
// For example, let us assume that
//
// class IntrinsicProjection : public SizedCostFunction<2, 5, 3> {
// public:
// IntrinsicProjection(const double* observation);
// virtual bool Evaluate(double const* const* parameters,
// double* residuals,
// double** jacobians) const;
// };
//
// is a cost function that implements the projection of a point in its
// local coordinate system onto its image plane and subtracts it from
// the observed point projection. It can compute its residual and
// either via analytic or numerical differentiation can compute its
// jacobians.
//
// Now we would like to compose the action of this CostFunction with
// the action of camera extrinsics, i.e., rotation and
// translation. Say we have a templated function
//
// template<typename T>
// void RotateAndTranslatePoint(const T* rotation,
// const T* translation,
// const T* point,
// T* result);
//
// Then we can now do the following,
//
// struct CameraProjection {
// CameraProjection(const double* observation)
// : intrinsic_projection_(new IntrinsicProjection(observation)) {
// }
// template <typename T>
// bool operator()(const T* rotation,
// const T* translation,
// const T* intrinsics,
// const T* point,
// T* residual) const {
// T transformed_point[3];
// RotateAndTranslatePoint(rotation, translation, point, transformed_point);
//
// // Note that we call intrinsic_projection_, just like it was
// // any other templated functor.
//
// return intrinsic_projection_(intrinsics, transformed_point, residual);
// }
//
// private:
// CostFunctionToFunctor<2,5,3> intrinsic_projection_;
// };
#ifndef CERES_PUBLIC_COST_FUNCTION_TO_FUNCTOR_H_
#define CERES_PUBLIC_COST_FUNCTION_TO_FUNCTOR_H_
#include <numeric>
#include <vector>
#include "ceres/cost_function.h"
#include "ceres/dynamic_cost_function_to_functor.h"
#include "ceres/internal/fixed_array.h"
#include "ceres/internal/port.h"
#include "ceres/internal/scoped_ptr.h"
namespace ceres {
template <int kNumResiduals,
int N0, int N1 = 0, int N2 = 0, int N3 = 0, int N4 = 0,
int N5 = 0, int N6 = 0, int N7 = 0, int N8 = 0, int N9 = 0>
class CostFunctionToFunctor {
public:
// Takes ownership of cost_function.
explicit CostFunctionToFunctor(CostFunction* cost_function)
: cost_functor_(cost_function) {
CHECK_NOTNULL(cost_function);
CHECK(kNumResiduals > 0 || kNumResiduals == DYNAMIC);
// This block breaks the 80 column rule to keep it somewhat readable.
CHECK((!N1 && !N2 && !N3 && !N4 && !N5 && !N6 && !N7 && !N8 && !N9) ||
((N1 > 0) && !N2 && !N3 && !N4 && !N5 && !N6 && !N7 && !N8 && !N9) ||
((N1 > 0) && (N2 > 0) && !N3 && !N4 && !N5 && !N6 && !N7 && !N8 && !N9) || // NOLINT
((N1 > 0) && (N2 > 0) && (N3 > 0) && !N4 && !N5 && !N6 && !N7 && !N8 && !N9) || // NOLINT
((N1 > 0) && (N2 > 0) && (N3 > 0) && (N4 > 0) && !N5 && !N6 && !N7 && !N8 && !N9) || // NOLINT
((N1 > 0) && (N2 > 0) && (N3 > 0) && (N4 > 0) && (N5 > 0) && !N6 && !N7 && !N8 && !N9) || // NOLINT
((N1 > 0) && (N2 > 0) && (N3 > 0) && (N4 > 0) && (N5 > 0) && (N6 > 0) && !N7 && !N8 && !N9) || // NOLINT
((N1 > 0) && (N2 > 0) && (N3 > 0) && (N4 > 0) && (N5 > 0) && (N6 > 0) && (N7 > 0) && !N8 && !N9) || // NOLINT
((N1 > 0) && (N2 > 0) && (N3 > 0) && (N4 > 0) && (N5 > 0) && (N6 > 0) && (N7 > 0) && (N8 > 0) && !N9) || // NOLINT
((N1 > 0) && (N2 > 0) && (N3 > 0) && (N4 > 0) && (N5 > 0) && (N6 > 0) && (N7 > 0) && (N8 > 0) && (N9 > 0))) // NOLINT
<< "Zero block cannot precede a non-zero block. Block sizes are "
<< "(ignore trailing 0s): " << N0 << ", " << N1 << ", " << N2 << ", "
<< N3 << ", " << N4 << ", " << N5 << ", " << N6 << ", " << N7 << ", "
<< N8 << ", " << N9;
const std::vector<int32>& parameter_block_sizes =
cost_function->parameter_block_sizes();
const int num_parameter_blocks =
(N0 > 0) + (N1 > 0) + (N2 > 0) + (N3 > 0) + (N4 > 0) +
(N5 > 0) + (N6 > 0) + (N7 > 0) + (N8 > 0) + (N9 > 0);
CHECK_EQ(parameter_block_sizes.size(), num_parameter_blocks);
CHECK_EQ(N0, parameter_block_sizes[0]);
if (parameter_block_sizes.size() > 1) CHECK_EQ(N1, parameter_block_sizes[1]); // NOLINT
if (parameter_block_sizes.size() > 2) CHECK_EQ(N2, parameter_block_sizes[2]); // NOLINT
if (parameter_block_sizes.size() > 3) CHECK_EQ(N3, parameter_block_sizes[3]); // NOLINT
if (parameter_block_sizes.size() > 4) CHECK_EQ(N4, parameter_block_sizes[4]); // NOLINT
if (parameter_block_sizes.size() > 5) CHECK_EQ(N5, parameter_block_sizes[5]); // NOLINT
if (parameter_block_sizes.size() > 6) CHECK_EQ(N6, parameter_block_sizes[6]); // NOLINT
if (parameter_block_sizes.size() > 7) CHECK_EQ(N7, parameter_block_sizes[7]); // NOLINT
if (parameter_block_sizes.size() > 8) CHECK_EQ(N8, parameter_block_sizes[8]); // NOLINT
if (parameter_block_sizes.size() > 9) CHECK_EQ(N9, parameter_block_sizes[9]); // NOLINT
CHECK_EQ(accumulate(parameter_block_sizes.begin(),
parameter_block_sizes.end(), 0),
N0 + N1 + N2 + N3 + N4 + N5 + N6 + N7 + N8 + N9);
}
bool operator()(const double* x0, double* residuals) const {
CHECK_NE(N0, 0);
CHECK_EQ(N1, 0);
CHECK_EQ(N2, 0);
CHECK_EQ(N3, 0);
CHECK_EQ(N4, 0);
CHECK_EQ(N5, 0);
CHECK_EQ(N6, 0);
CHECK_EQ(N7, 0);
CHECK_EQ(N8, 0);
CHECK_EQ(N9, 0);
return cost_functor_(&x0, residuals);
}
bool operator()(const double* x0,
const double* x1,
double* residuals) const {
CHECK_NE(N0, 0);
CHECK_NE(N1, 0);
CHECK_EQ(N2, 0);
CHECK_EQ(N3, 0);
CHECK_EQ(N4, 0);
CHECK_EQ(N5, 0);
CHECK_EQ(N6, 0);
CHECK_EQ(N7, 0);
CHECK_EQ(N8, 0);
CHECK_EQ(N9, 0);
internal::FixedArray<const double*> parameter_blocks(2);
parameter_blocks[0] = x0;
parameter_blocks[1] = x1;
return cost_functor_(parameter_blocks.get(), residuals);
}
bool operator()(const double* x0,
const double* x1,
const double* x2,
double* residuals) const {
CHECK_NE(N0, 0);
CHECK_NE(N1, 0);
CHECK_NE(N2, 0);
CHECK_EQ(N3, 0);
CHECK_EQ(N4, 0);
CHECK_EQ(N5, 0);
CHECK_EQ(N6, 0);
CHECK_EQ(N7, 0);
CHECK_EQ(N8, 0);
CHECK_EQ(N9, 0);
internal::FixedArray<const double*> parameter_blocks(3);
parameter_blocks[0] = x0;
parameter_blocks[1] = x1;
parameter_blocks[2] = x2;
return cost_functor_(parameter_blocks.get(), residuals);
}
bool operator()(const double* x0,
const double* x1,
const double* x2,
const double* x3,
double* residuals) const {
CHECK_NE(N0, 0);
CHECK_NE(N1, 0);
CHECK_NE(N2, 0);
CHECK_NE(N3, 0);
CHECK_EQ(N4, 0);
CHECK_EQ(N5, 0);
CHECK_EQ(N6, 0);
CHECK_EQ(N7, 0);
CHECK_EQ(N8, 0);
CHECK_EQ(N9, 0);
internal::FixedArray<const double*> parameter_blocks(4);
parameter_blocks[0] = x0;
parameter_blocks[1] = x1;
parameter_blocks[2] = x2;
parameter_blocks[3] = x3;
return cost_functor_(parameter_blocks.get(), residuals);
}
bool operator()(const double* x0,
const double* x1,
const double* x2,
const double* x3,
const double* x4,
double* residuals) const {
CHECK_NE(N0, 0);
CHECK_NE(N1, 0);
CHECK_NE(N2, 0);
CHECK_NE(N3, 0);
CHECK_NE(N4, 0);
CHECK_EQ(N5, 0);
CHECK_EQ(N6, 0);
CHECK_EQ(N7, 0);
CHECK_EQ(N8, 0);
CHECK_EQ(N9, 0);
internal::FixedArray<const double*> parameter_blocks(5);
parameter_blocks[0] = x0;
parameter_blocks[1] = x1;
parameter_blocks[2] = x2;
parameter_blocks[3] = x3;
parameter_blocks[4] = x4;
return cost_functor_(parameter_blocks.get(), residuals);
}
bool operator()(const double* x0,
const double* x1,
const double* x2,
const double* x3,
const double* x4,
const double* x5,
double* residuals) const {
CHECK_NE(N0, 0);
CHECK_NE(N1, 0);
CHECK_NE(N2, 0);
CHECK_NE(N3, 0);
CHECK_NE(N4, 0);
CHECK_NE(N5, 0);
CHECK_EQ(N6, 0);
CHECK_EQ(N7, 0);
CHECK_EQ(N8, 0);
CHECK_EQ(N9, 0);
internal::FixedArray<const double*> parameter_blocks(6);
parameter_blocks[0] = x0;
parameter_blocks[1] = x1;
parameter_blocks[2] = x2;
parameter_blocks[3] = x3;
parameter_blocks[4] = x4;
parameter_blocks[5] = x5;
return cost_functor_(parameter_blocks.get(), residuals);
}
bool operator()(const double* x0,
const double* x1,
const double* x2,
const double* x3,
const double* x4,
const double* x5,
const double* x6,
double* residuals) const {
CHECK_NE(N0, 0);
CHECK_NE(N1, 0);
CHECK_NE(N2, 0);
CHECK_NE(N3, 0);
CHECK_NE(N4, 0);
CHECK_NE(N5, 0);
CHECK_NE(N6, 0);
CHECK_EQ(N7, 0);
CHECK_EQ(N8, 0);
CHECK_EQ(N9, 0);
internal::FixedArray<const double*> parameter_blocks(7);
parameter_blocks[0] = x0;
parameter_blocks[1] = x1;
parameter_blocks[2] = x2;
parameter_blocks[3] = x3;
parameter_blocks[4] = x4;
parameter_blocks[5] = x5;
parameter_blocks[6] = x6;
return cost_functor_(parameter_blocks.get(), residuals);
}
bool operator()(const double* x0,
const double* x1,
const double* x2,
const double* x3,
const double* x4,
const double* x5,
const double* x6,
const double* x7,
double* residuals) const {
CHECK_NE(N0, 0);
CHECK_NE(N1, 0);
CHECK_NE(N2, 0);
CHECK_NE(N3, 0);
CHECK_NE(N4, 0);
CHECK_NE(N5, 0);
CHECK_NE(N6, 0);
CHECK_NE(N7, 0);
CHECK_EQ(N8, 0);
CHECK_EQ(N9, 0);
internal::FixedArray<const double*> parameter_blocks(8);
parameter_blocks[0] = x0;
parameter_blocks[1] = x1;
parameter_blocks[2] = x2;
parameter_blocks[3] = x3;
parameter_blocks[4] = x4;
parameter_blocks[5] = x5;
parameter_blocks[6] = x6;
parameter_blocks[7] = x7;
return cost_functor_(parameter_blocks.get(), residuals);
}
bool operator()(const double* x0,
const double* x1,
const double* x2,
const double* x3,
const double* x4,
const double* x5,
const double* x6,
const double* x7,
const double* x8,
double* residuals) const {
CHECK_NE(N0, 0);
CHECK_NE(N1, 0);
CHECK_NE(N2, 0);
CHECK_NE(N3, 0);
CHECK_NE(N4, 0);
CHECK_NE(N5, 0);
CHECK_NE(N6, 0);
CHECK_NE(N7, 0);
CHECK_NE(N8, 0);
CHECK_EQ(N9, 0);
internal::FixedArray<const double*> parameter_blocks(9);
parameter_blocks[0] = x0;
parameter_blocks[1] = x1;
parameter_blocks[2] = x2;
parameter_blocks[3] = x3;
parameter_blocks[4] = x4;
parameter_blocks[5] = x5;
parameter_blocks[6] = x6;
parameter_blocks[7] = x7;
parameter_blocks[8] = x8;
return cost_functor_(parameter_blocks.get(), residuals);
}
bool operator()(const double* x0,
const double* x1,
const double* x2,
const double* x3,
const double* x4,
const double* x5,
const double* x6,
const double* x7,
const double* x8,
const double* x9,
double* residuals) const {
CHECK_NE(N0, 0);
CHECK_NE(N1, 0);
CHECK_NE(N2, 0);
CHECK_NE(N3, 0);
CHECK_NE(N4, 0);
CHECK_NE(N5, 0);
CHECK_NE(N6, 0);
CHECK_NE(N7, 0);
CHECK_NE(N8, 0);
CHECK_NE(N9, 0);
internal::FixedArray<const double*> parameter_blocks(10);
parameter_blocks[0] = x0;
parameter_blocks[1] = x1;
parameter_blocks[2] = x2;
parameter_blocks[3] = x3;
parameter_blocks[4] = x4;
parameter_blocks[5] = x5;
parameter_blocks[6] = x6;
parameter_blocks[7] = x7;
parameter_blocks[8] = x8;
parameter_blocks[9] = x9;
return cost_functor_(parameter_blocks.get(), residuals);
}
template <typename JetT>
bool operator()(const JetT* x0, JetT* residuals) const {
CHECK_NE(N0, 0);
CHECK_EQ(N1, 0);
CHECK_EQ(N2, 0);
CHECK_EQ(N3, 0);
CHECK_EQ(N4, 0);
CHECK_EQ(N5, 0);
CHECK_EQ(N6, 0);
CHECK_EQ(N7, 0);
CHECK_EQ(N8, 0);
CHECK_EQ(N9, 0);
return cost_functor_(&x0, residuals);
}
template <typename JetT>
bool operator()(const JetT* x0,
const JetT* x1,
JetT* residuals) const {
CHECK_NE(N0, 0);
CHECK_NE(N1, 0);
CHECK_EQ(N2, 0);
CHECK_EQ(N3, 0);
CHECK_EQ(N4, 0);
CHECK_EQ(N5, 0);
CHECK_EQ(N6, 0);
CHECK_EQ(N7, 0);
CHECK_EQ(N8, 0);
CHECK_EQ(N9, 0);
internal::FixedArray<const JetT*> jets(2);
jets[0] = x0;
jets[1] = x1;
return cost_functor_(jets.get(), residuals);
}
template <typename JetT>
bool operator()(const JetT* x0,
const JetT* x1,
const JetT* x2,
JetT* residuals) const {
CHECK_NE(N0, 0);
CHECK_NE(N1, 0);
CHECK_NE(N2, 0);
CHECK_EQ(N3, 0);
CHECK_EQ(N4, 0);
CHECK_EQ(N5, 0);
CHECK_EQ(N6, 0);
CHECK_EQ(N7, 0);
CHECK_EQ(N8, 0);
CHECK_EQ(N9, 0);
internal::FixedArray<const JetT*> jets(3);
jets[0] = x0;
jets[1] = x1;
jets[2] = x2;
return cost_functor_(jets.get(), residuals);
}
template <typename JetT>
bool operator()(const JetT* x0,
const JetT* x1,
const JetT* x2,
const JetT* x3,
JetT* residuals) const {
CHECK_NE(N0, 0);
CHECK_NE(N1, 0);
CHECK_NE(N2, 0);
CHECK_NE(N3, 0);
CHECK_EQ(N4, 0);
CHECK_EQ(N5, 0);
CHECK_EQ(N6, 0);
CHECK_EQ(N7, 0);
CHECK_EQ(N8, 0);
CHECK_EQ(N9, 0);
internal::FixedArray<const JetT*> jets(4);
jets[0] = x0;
jets[1] = x1;
jets[2] = x2;
jets[3] = x3;
return cost_functor_(jets.get(), residuals);
}
template <typename JetT>
bool operator()(const JetT* x0,
const JetT* x1,
const JetT* x2,
const JetT* x3,
const JetT* x4,
JetT* residuals) const {
CHECK_NE(N0, 0);
CHECK_NE(N1, 0);
CHECK_NE(N2, 0);
CHECK_NE(N3, 0);
CHECK_NE(N4, 0);
CHECK_EQ(N5, 0);
CHECK_EQ(N6, 0);
CHECK_EQ(N7, 0);
CHECK_EQ(N8, 0);
CHECK_EQ(N9, 0);
internal::FixedArray<const JetT*> jets(5);
jets[0] = x0;
jets[1] = x1;
jets[2] = x2;
jets[3] = x3;
jets[4] = x4;
return cost_functor_(jets.get(), residuals);
}
template <typename JetT>
bool operator()(const JetT* x0,
const JetT* x1,
const JetT* x2,
const JetT* x3,
const JetT* x4,
const JetT* x5,
JetT* residuals) const {
CHECK_NE(N0, 0);
CHECK_NE(N1, 0);
CHECK_NE(N2, 0);
CHECK_NE(N3, 0);
CHECK_NE(N4, 0);
CHECK_NE(N5, 0);
CHECK_EQ(N6, 0);
CHECK_EQ(N7, 0);
CHECK_EQ(N8, 0);
CHECK_EQ(N9, 0);
internal::FixedArray<const JetT*> jets(6);
jets[0] = x0;
jets[1] = x1;
jets[2] = x2;
jets[3] = x3;
jets[4] = x4;
jets[5] = x5;
return cost_functor_(jets.get(), residuals);
}
template <typename JetT>
bool operator()(const JetT* x0,
const JetT* x1,
const JetT* x2,
const JetT* x3,
const JetT* x4,
const JetT* x5,
const JetT* x6,
JetT* residuals) const {
CHECK_NE(N0, 0);
CHECK_NE(N1, 0);
CHECK_NE(N2, 0);
CHECK_NE(N3, 0);
CHECK_NE(N4, 0);
CHECK_NE(N5, 0);
CHECK_NE(N6, 0);
CHECK_EQ(N7, 0);
CHECK_EQ(N8, 0);
CHECK_EQ(N9, 0);
internal::FixedArray<const JetT*> jets(7);
jets[0] = x0;
jets[1] = x1;
jets[2] = x2;
jets[3] = x3;
jets[4] = x4;
jets[5] = x5;
jets[6] = x6;
return cost_functor_(jets.get(), residuals);
}
template <typename JetT>
bool operator()(const JetT* x0,
const JetT* x1,
const JetT* x2,
const JetT* x3,
const JetT* x4,
const JetT* x5,
const JetT* x6,
const JetT* x7,
JetT* residuals) const {
CHECK_NE(N0, 0);
CHECK_NE(N1, 0);
CHECK_NE(N2, 0);
CHECK_NE(N3, 0);
CHECK_NE(N4, 0);
CHECK_NE(N5, 0);
CHECK_NE(N6, 0);
CHECK_NE(N7, 0);
CHECK_EQ(N8, 0);
CHECK_EQ(N9, 0);
internal::FixedArray<const JetT*> jets(8);
jets[0] = x0;
jets[1] = x1;
jets[2] = x2;
jets[3] = x3;
jets[4] = x4;
jets[5] = x5;
jets[6] = x6;
jets[7] = x7;
return cost_functor_(jets.get(), residuals);
}
template <typename JetT>
bool operator()(const JetT* x0,
const JetT* x1,
const JetT* x2,
const JetT* x3,
const JetT* x4,
const JetT* x5,
const JetT* x6,
const JetT* x7,
const JetT* x8,
JetT* residuals) const {
CHECK_NE(N0, 0);
CHECK_NE(N1, 0);
CHECK_NE(N2, 0);
CHECK_NE(N3, 0);
CHECK_NE(N4, 0);
CHECK_NE(N5, 0);
CHECK_NE(N6, 0);
CHECK_NE(N7, 0);
CHECK_NE(N8, 0);
CHECK_EQ(N9, 0);
internal::FixedArray<const JetT*> jets(9);
jets[0] = x0;
jets[1] = x1;
jets[2] = x2;
jets[3] = x3;
jets[4] = x4;
jets[5] = x5;
jets[6] = x6;
jets[7] = x7;
jets[8] = x8;
return cost_functor_(jets.get(), residuals);
}
template <typename JetT>
bool operator()(const JetT* x0,
const JetT* x1,
const JetT* x2,
const JetT* x3,
const JetT* x4,
const JetT* x5,
const JetT* x6,
const JetT* x7,
const JetT* x8,
const JetT* x9,
JetT* residuals) const {
CHECK_NE(N0, 0);
CHECK_NE(N1, 0);
CHECK_NE(N2, 0);
CHECK_NE(N3, 0);
CHECK_NE(N4, 0);
CHECK_NE(N5, 0);
CHECK_NE(N6, 0);
CHECK_NE(N7, 0);
CHECK_NE(N8, 0);
CHECK_NE(N9, 0);
internal::FixedArray<const JetT*> jets(10);
jets[0] = x0;
jets[1] = x1;
jets[2] = x2;
jets[3] = x3;
jets[4] = x4;
jets[5] = x5;
jets[6] = x6;
jets[7] = x7;
jets[8] = x8;
jets[9] = x9;
return cost_functor_(jets.get(), residuals);
}
private:
DynamicCostFunctionToFunctor cost_functor_;
};
} // namespace ceres
#endif // CERES_PUBLIC_COST_FUNCTION_TO_FUNCTOR_H_