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添加字符串向量和不同数据类型向量的映射

vector c++

Akshay shubaly · 技术社区 · 7 年前

如中所示 https://stackoverflow.com/a/44884240/3782963 std::map<std::string, Spikes::data> get_data1() struct 打电话 data

struct data {

            std::vector<Eigen::MatrixXd> samples;
            std::vector<std::string> sample_names;
            int index = -1;
        };

把它放在我的 namespace FileReader .

我的方法如下:

std::map<std::string, Spikes::data> FileReader::get_data1() {
    std::map<std::string, Spikes::data> content;

    std::vector<Eigen::MatrixXd> samples;
    std::vector<std::string> sample_names;

    for (auto i : list_dir()) {
        if (contains_number(i)) {
            samples.push_back(load_csv(location + "/" + i));
            sample_names.push_back(i);
        }
    }

    content.emplace(std::make_pair("samples", Spikes::data{samples,0}));
    content.emplace(std::make_pair("sample_names", Spikes::data{sample_names,1}));

    return content;

在我的 main.cpp 我将此方法称为:

for (auto i:a.get_data1()["samples"].samples){
        std::cout<<i;
    }

/cygdrive/c/Users/aksha/Box Sync/MyDrive/Projects/Akshay-GitHub/libSpikes/libSpikes/src/Core/FileReader.cpp: In member function 'std::map<std::basic_string<char>, Spikes::data> Spikes::FileReader::get_data1()':
/cygdrive/c/Users/aksha/Box Sync/MyDrive/Projects/Akshay-GitHub/libSpikes/libSpikes/src/Core/FileReader.cpp:154:69: error: no matching function for call to 'Spikes::data::data(<brace-enclosed initializer list>)'
     content.emplace(std::make_pair("samples", Spikes::data{samples,0}));
                                                                     ^
In file included from /cygdrive/c/Users/aksha/Box Sync/MyDrive/Projects/Akshay-GitHub/libSpikes/libSpikes/src/Core/FileReader.cpp:3:0:
/cygdrive/c/Users/aksha/Box Sync/MyDrive/Projects/Akshay-GitHub/libSpikes/libSpikes/src/Core/FileReader.h:13:12: note: candidate: Spikes::data::data()
     struct data {
            ^
/cygdrive/c/Users/aksha/Box Sync/MyDrive/Projects/Akshay-GitHub/libSpikes/libSpikes/src/Core/FileReader.h:13:12: note:   candidate expects 0 arguments, 2 provided
/cygdrive/c/Users/aksha/Box Sync/MyDrive/Projects/Akshay-GitHub/libSpikes/libSpikes/src/Core/FileReader.h:13:12: note: candidate: Spikes::data::data(const Spikes::data&)
/cygdrive/c/Users/aksha/Box Sync/MyDrive/Projects/Akshay-GitHub/libSpikes/libSpikes/src/Core/FileReader.h:13:12: note:   candidate expects 1 argument, 2 provided
/cygdrive/c/Users/aksha/Box Sync/MyDrive/Projects/Akshay-GitHub/libSpikes/libSpikes/src/Core/FileReader.h:13:12: note: candidate: Spikes::data::data(Spikes::data&&)
/cygdrive/c/Users/aksha/Box Sync/MyDrive/Projects/Akshay-GitHub/libSpikes/libSpikes/src/Core/FileReader.h:13:12: note:   candidate expects 1 argument, 2 provided
/cygdrive/c/Users/aksha/Box Sync/MyDrive/Projects/Akshay-GitHub/libSpikes/libSpikes/src/Core/FileReader.cpp:155:79: error: no matching function for call to 'Spikes::data::data(<brace-enclosed initializer list>)'
     content.emplace(std::make_pair("sample_names", Spikes::data{sample_names,1}));
                                                                               ^
In file included from /cygdrive/c/Users/aksha/Box Sync/MyDrive/Projects/Akshay-GitHub/libSpikes/libSpikes/src/Core/FileReader.cpp:3:0:
/cygdrive/c/Users/aksha/Box Sync/MyDrive/Projects/Akshay-GitHub/libSpikes/libSpikes/src/Core/FileReader.h:13:12: note: candidate: Spikes::data::data()
     struct data {
            ^
/cygdrive/c/Users/aksha/Box Sync/MyDrive/Projects/Akshay-GitHub/libSpikes/libSpikes/src/Core/FileReader.h:13:12: note:   candidate expects 0 arguments, 2 provided
/cygdrive/c/Users/aksha/Box Sync/MyDrive/Projects/Akshay-GitHub/libSpikes/libSpikes/src/Core/FileReader.h:13:12: note: candidate: Spikes::data::data(const Spikes::data&)
/cygdrive/c/Users/aksha/Box Sync/MyDrive/Projects/Akshay-GitHub/libSpikes/libSpikes/src/Core/FileReader.h:13:12: note:   candidate expects 1 argument, 2 provided
/cygdrive/c/Users/aksha/Box Sync/MyDrive/Projects/Akshay-GitHub/libSpikes/libSpikes/src/Core/FileReader.h:13:12: note: candidate: Spikes::data::data(Spikes::data&&)
/cygdrive/c/Users/aksha/Box Sync/MyDrive/Projects/Akshay-GitHub/libSpikes/libSpikes/src/Core/FileReader.h:13:12: note:   candidate expects 1 argument, 2 provided

我甚至尝试过:

content["samples"] = Spikes::data{samples,0};
content["sample_names"] = Spikes::data{sample_names,1};

我还是会犯同样的错误。任何帮助都将不胜感激。

2 回复 | 直到 7 年前

Dean Seo 7 年前

如中所示 https://stackoverflow.com/a/44884240/3782963 .我创建了一个返回类型为std::map get\u data1()的方法。

施工人员 对于 data

struct data 
{
    // constructors... <- here

    std::vector<Eigen::MatrixXd> samples;
    std::vector<std::string> names;
    int index = -1;
};

@SamVarshavchik很好地描述了原因。

// Constructors
data(std::vector<Eigen::MatrixXd> && rhs, int idx) 
{
    samples = std::move(rhs);
    index = idx;
}

data(std::vector<std::string> && rhs, int idx) 
{
    samples = std::move(rhs);
    index = idx;
}

content.emplace(std::make_pair("samples", Spikes::data{ std::move(samples), 0}));
content.emplace(std::make_pair("sample_names", Spikes::data{ std::move(sample_names), 1}));

Sam Varshavchik 7 年前

当您对简单结构/聚合等使用值初始化时:

Spikes::data{samples,0}

你的 data 类包含三个成员,前两个是向量,第三个是 int std::vector 属于 std::string s使用普通整数 0 不会去任何地方。这 0 将被解释为初始化 struct ,因为它是初始化列表中的第二个值。您的第二个成员是一个属于 s、编译器将尝试相应地初始化第二个成员,如下所示:

std::vector<std::string> sample_names{0};

在使用值初始化时,不能任意跳过类成员。您必须按顺序初始化每个类成员。在这种情况下,您可能的意图可能是以下几点:

Spikes::data{samples,{},0}

因此,使用空的子初始化列表初始化第二个向量。同样,您的第二次初始化尝试:

Spikes::data{sample_names,1}

Spikes::data{{}, sample_names,1}}

i、 e.初始化第一个 标准::矢量 初始化列表为空的成员,然后初始化第二个照着