初始化类成员初始值设定项列表中的向量元组

Question

我有一个数据结构：

using Delaunay = CGAL::Delaunay_triangulation_3<K, Tds>;
using Cell_handle = Delaunay::Cell_handle;
using Vertex_handle = Delaunay::Vertex_handle;
using Edge_handle = std::tuple<Cell_handle, std::uintmax_t, std::uintmax_t>;
using geometry_tuple = std::tuple<std::vector<Cell_handle>,
                              std::vector<Cell_handle>,
                              std::vector<Cell_handle>,
                              std::vector<Edge_handle>,
                              std::uintmax_t,
                              std::vector<Vertex_handle>>;

我想在默认构造函数中初始化：

struct SimplicialManifold {
///  Default constructor with proper initialization
SimplicialManifold()
      : triangulation{std::make_unique<Delaunay>()},
        geometry{std::make_tuple(0, 0, 0, 0, 0, 0)} {}
std::unique_ptr<Delaunay> triangulation;
///< std::unique_ptr to the Delaunay triangulation
geometry_tuple geometry;
///< The geometric structure of the triangulation
};

上面的代码在Apple LLVM版本7.3.0（clang-703.0.29）中有效，但在GCC 5.2中失败，有大量模板编译器goo：

../src/S3Triangulation.h: In constructor ‘SimplicialManifold::SimplicialManifold()’../src/S3Triangulation.h:493:55: error: no matching function for call to
 ‘std::tuple<std::vector<CGAL::CCC_internal::CCC_iterator<CGAL::Concurrent_compact_container<CGAL::Triangulation_cell_base_with_info_3<long unsigned int, CGAL::Epick, CGAL::Triangulation_cell_base_3<CGAL::Epick, CGAL::Triangulation_ds_cell_base_3<CGAL::Triangulation_data_structure_3<CGAL::Triangulation_vertex_base_with_info_3<long unsigned int, CGAL::Epick, CGAL::Triangulation_vertex_base_3<CGAL::Epick, CGAL::Triangulation_ds_vertex_base_3<void> > >, CGAL::Triangulation_cell_base_with_info_3<long unsigned int, CGAL::Epick, CGAL::Triangulation_cell_base_3<CGAL::Epick, CGAL::Triangulation_ds_cell_base_3<void> > >, CGAL::Parallel_tag> > > >, tbb::scalable_allocator<CGAL::Triangulation_cell_base_with_info_3<long unsigned int, CGAL::Epick, CGAL::Triangulation_cell_base_3<CGAL::Epick, CGAL::Triangulation_ds_cell_base_3<CGAL::Triangulation_data_structure_3<CGAL::Triangulation_vertex_base_with_info_3<long unsigned int, CGAL::Epick, CGAL::Triangulation_vertex_base_3<CGAL::Epick, CGAL::Triangulation_ds_vertex_base_3<void> > >, CGAL::Triangulation_cell_base_with_info_3<long unsigned int, CGAL::Epick, CGAL::Triangulation_cell_base_3<CGAL::Epick, CGAL::Triangulation_ds_cell_base_3<void> > >, CGAL::Parallel_tag> > > > > >, false>, std::allocator<CGAL::CCC_internal::CCC_iterator<CGAL::Concurrent_compact_container<CGAL::Triangulation_cell_base_with_info_3<long unsigned int, CGAL::Epick, CGAL::Triangulation_cell_base_3<CGAL::Epick,

（有问题的代码 https://github.com/acgetchell/CDT-plusplus/blob/functional/src/S3Triangulation.h 从第 467 行开始。

我查看了初始值设定项列表，但这些列表不起作用：

geometry{std::initializer_list<std::vector<Cell_handle>,
                std::vector<Cell_handle>,
                std::vector<Cell_handle>,
                std::vector<Edge_handle>,
                std::uintmax_t,
                std::vector<Vertex_handle>>({0, 0, 0, 0, 0, 0})
        } {}

关于如何做到这一点并使海湾合作委员会满意的建议？

Answer 1

最好的解决方案是编写一个正确的结构或类，而不是滥用std::tuple。 例如：

struct geometry_tuple
{
    std::array<std::vector<Cell_handle>, 3> cells;
    std::vector<Edge_handle> edges;
    std::uintmax_t max;
    std::vector<Vertex_handle> vertexes;
    geometry_tuple()
        : max(0)
    {
        // ...
    }
};

通过为每个字段提供描述性名称，而不是稍后执行.get<2>()等，这使您的代码更清晰。 它允许您使用您可能需要的任何参数制作适当的构造函数。