Eigen/src/Core/util/StaticAssert.h

// This file is part of Eigen, a lightweight C++ template library
// for linear algebra. Eigen itself is part of the KDE project.
//
// Copyright (C) 2008 Gael Guennebaud <g.gael@free.fr>
// Copyright (C) 2006-2008 Benoit Jacob <jacob.benoit.1@gmail.com>
//
// Eigen is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 3 of the License, or (at your option) any later version.
//
// Alternatively, you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
// published by the Free Software Foundation; either version 2 of
// the License, or (at your option) any later version.
//
// Eigen is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
// FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License or the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License and a copy of the GNU General Public License along with
// Eigen. If not, see <http://www.gnu.org/licenses/>.

#ifndef EIGEN_STATIC_ASSERT_H
#define EIGEN_STATIC_ASSERT_H

/* Some notes on Eigen's static assertion mechanism:
 *
 *  - in EIGEN_STATIC_ASSERT(CONDITION,MSG) the parameter CONDITION must be a compile time boolean
 *    expression, and MSG an enum listed in struct ei_static_assert<true>
 *
 *  - define EIGEN_NO_STATIC_ASSERT to disable them (and save compilation time)
 *    in that case, the static assertion is converted to the following runtime assert:
 *      ei_assert(CONDITION && "MSG")
 *
 *  - currently EIGEN_STATIC_ASSERT can only be used in function scope
 *
 */

#ifndef EIGEN_NO_STATIC_ASSERT

  #ifdef __GXX_EXPERIMENTAL_CXX0X__

    // if native static_assert is enabled, let's use it
    #define EIGEN_STATIC_ASSERT(X,MSG) static_assert(X,#MSG);

  #else // CXX0X

    template<bool condition>
    struct ei_static_assert {};

    template<>
    struct ei_static_assert<true>
    {
      enum {
        you_tried_calling_a_vector_method_on_a_matrix,
        you_mixed_vectors_of_different_sizes,
        you_mixed_matrices_of_different_sizes,
        this_method_is_only_for_vectors_of_a_specific_size,
        this_method_is_only_for_matrices_of_a_specific_size,
        you_made_a_programming_mistake,
        you_called_a_fixed_size_method_on_a_dynamic_size_matrix_or_vector,
        unaligned_load_and_store_operations_unimplemented_on_AltiVec,
        numeric_type_must_be_floating_point,
        coefficient_write_access_to_selfadjoint_not_supported,
        writing_to_triangular_part_with_unit_diagonal_is_not_supported,
        this_method_is_only_for_fixed_size,
        invalid_matrix_product,
        invalid_vector_vector_product__if_you_wanted_a_dot_or_coeff_wise_product_you_must_use_the_explicit_functions,
        invalid_matrix_product__if_you_wanted_a_coeff_wise_product_you_must_use_the_explicit_function,
        you_mixed_different_numeric_types__you_need_to_use_the_cast_method_of_MatrixBase_to_cast_numeric_types_explicitly
      };
    };

    #define EIGEN_STATIC_ASSERT(CONDITION,MSG) \
      if (Eigen::ei_static_assert<CONDITION ? true : false>::MSG) {}

  #endif // not CXX0X

#else // EIGEN_NO_STATIC_ASSERT

  #define EIGEN_STATIC_ASSERT(CONDITION,MSG) ei_assert((CONDITION) && #MSG);

#endif // EIGEN_NO_STATIC_ASSERT


// static assertion failing if the type \a TYPE is not a vector type
#define EIGEN_STATIC_ASSERT_VECTOR_ONLY(TYPE) \
  EIGEN_STATIC_ASSERT(TYPE::IsVectorAtCompileTime, \
                      you_tried_calling_a_vector_method_on_a_matrix)

// static assertion failing if the type \a TYPE is not fixed-size
#define EIGEN_STATIC_ASSERT_FIXED_SIZE(TYPE) \
  EIGEN_STATIC_ASSERT(TYPE::SizeAtCompileTime!=Eigen::Dynamic, \
                      you_called_a_fixed_size_method_on_a_dynamic_size_matrix_or_vector)

// static assertion failing if the type \a TYPE is not a vector type of the given size
#define EIGEN_STATIC_ASSERT_VECTOR_SPECIFIC_SIZE(TYPE, SIZE) \
  EIGEN_STATIC_ASSERT(TYPE::IsVectorAtCompileTime && TYPE::SizeAtCompileTime==SIZE, \
                      this_method_is_only_for_vectors_of_a_specific_size)

// static assertion failing if the type \a TYPE is not a vector type of the given size
#define EIGEN_STATIC_ASSERT_MATRIX_SPECIFIC_SIZE(TYPE, ROWS, COLS) \
  EIGEN_STATIC_ASSERT(TYPE::RowsAtCompileTime==ROWS && TYPE::ColsAtCompileTime==COLS, \
                      this_method_is_only_for_matrices_of_a_specific_size)

// static assertion failing if the two vector expression types are not compatible (same fixed-size or dynamic size)
#define EIGEN_STATIC_ASSERT_SAME_VECTOR_SIZE(TYPE0,TYPE1) \
  EIGEN_STATIC_ASSERT( \
      (int(TYPE0::SizeAtCompileTime)==Eigen::Dynamic \
    || int(TYPE1::SizeAtCompileTime)==Eigen::Dynamic \
    || int(TYPE0::SizeAtCompileTime)==int(TYPE1::SizeAtCompileTime)),\
    you_mixed_vectors_of_different_sizes)

#define EIGEN_PREDICATE_SAME_MATRIX_SIZE(TYPE0,TYPE1) \
      ((int(TYPE0::RowsAtCompileTime)==Eigen::Dynamic \
    || int(TYPE1::RowsAtCompileTime)==Eigen::Dynamic \
    || int(TYPE0::RowsAtCompileTime)==int(TYPE1::RowsAtCompileTime)) \
   && (int(TYPE0::ColsAtCompileTime)==Eigen::Dynamic \
    || int(TYPE1::ColsAtCompileTime)==Eigen::Dynamic \
    || int(TYPE0::ColsAtCompileTime)==int(TYPE1::ColsAtCompileTime)))

// static assertion failing if it is guaranteed at compile-time that the two matrix expression types have different sizes
#define EIGEN_STATIC_ASSERT_SAME_MATRIX_SIZE(TYPE0,TYPE1) \
  EIGEN_STATIC_ASSERT( \
     EIGEN_PREDICATE_SAME_MATRIX_SIZE(TYPE0,TYPE1),\
    you_mixed_matrices_of_different_sizes)

#endif // EIGEN_STATIC_ASSERT_H