在 std::vector 处没有可行的重载 '='

Question

我有这个 c++ 程序具有以下类型：

typedef pcl::PointXYZI PointType;
typedef pcl::PointCloud<PointType> PointCloudType;
typedef std::vector<PointCloudType::Ptr> CloudPtrList;

这主要是：

CloudPtrList clusterPtr(2);
   
    for (int i = 0; i < clusterPtr.size(); ++i)
    {
        clusterPtr[i] = boost::make_shared<PointCloudType>();
    }

当我尝试初始化这个向量时，我不断收到这个错误“没有可行的重载=”（上面的）

clusterPtr[i] = boost::make_shared<PointCloudType>();

这是完整的错误：

 No viable overloaded '='

/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/memory:3737:17: Candidate function not viable: no known conversion from 'typename boost::detail::sp_if_not_array<PointCloud<PointXYZI> >::type' (aka 'shared_ptr<pcl::PointCloud<pcl::PointXYZI> >') to 'const std::__1::shared_ptr<pcl::PointCloud<pcl::PointXYZI> >' for 1st argument
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/memory:3748:17: Candidate function not viable: no known conversion from 'typename boost::detail::sp_if_not_array<PointCloud<PointXYZI> >::type' (aka 'shared_ptr<pcl::PointCloud<pcl::PointXYZI> >') to 'std::__1::shared_ptr<pcl::PointCloud<pcl::PointXYZI> >' for 1st argument
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/memory:3745:9: Candidate template ignored: could not match 'std::__1::shared_ptr' against 'boost::shared_ptr'
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/memory:3756:9: Candidate template ignored: could not match 'std::__1::shared_ptr' against 'boost::shared_ptr'
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/memory:3766:9: Candidate template ignored: could not match 'auto_ptr' against 'shared_ptr'
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/memory:3790:9: Candidate template ignored: could not match 'unique_ptr' against 'shared_ptr'

Answer 1

从错误消息中可以看出...

/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/memory:3737:17: Candidate function not viable: no known conversion from 'typename boost::detail::sp_if_not_array<PointCloud<PointXYZI> >::type' (aka 'shared_ptr<pcl::PointCloud<pcl::PointXYZI> >') to 'const std::__1::shared_ptr<pcl::PointCloud<pcl::PointXYZI> >' for 1st argument
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/memory:3748:17: Candidate function not viable: no known conversion from 'typename boost::detail::sp_if_not_array<PointCloud<PointXYZI> >::type' (aka 'shared_ptr<pcl::PointCloud<pcl::PointXYZI> >') to 'std::__1::shared_ptr<pcl::PointCloud<pcl::PointXYZI> >' for 1st argument

...您正在使用更新版本的PCL ，其中boost::shared_ptr已被替换为std::shared_ptr ：

#include <pcl/common/projection_matrix.h>
#include <pcl/point_types.h>

//#include <boost/make_shared.hpp>   // boost::make_shared
#include <memory>                    // std::make_shared

typedef pcl::PointCloud<pcl::PointXYZI> PointCloudType;

int main() {
    std::vector<PointCloudType::Ptr> clusterPtr(2);

    for(int i = 0; i < clusterPtr.size(); ++i) {
        clusterPtr[i] = std::make_shared<PointCloudType>();   // std::make_shared
    }
}