'stoi'和'to_string'不是'std'的成员， [英] 'stoi' and 'to_string' is not a member of 'std'

问题描述

我有一些代码，它相当大，所以我只是在这里创建一个快照：

  int l = 3; 
 vector< int>权重; 
 
 void changeWeights（int out）{
 for（int i = 0; i  int w = std :: stoi std :: to_string（weights [i]）） -  
 out * std :: stoi（std :: to_string（weights [i]））; 
 if（w <-l）{
 w = -l; 
} else if（w> l）{
 w = 1; 
} 
 weights.assign（i，w）; 
} 
} 
  

我在'stoi' to_string'以

形式的函数调用

  Main.cpp：35：21：error：'stoi' 'std'
 int w = std :: stoi（std :: to_string（weights [i]）） -  
 ^ 
 Main.cpp：35：31：error：'to_string'is不是'std'的成员
 int w = std :: stoi（std :: to_string（weights [i]）） -  
 ^ 
 Main.cpp：36：17： 'stoi'不是'std'的成员
 out * std :: stoi（std :: to_string（weights [i]））; 
 ^ 
 Main.cpp：36：27：error：'to_string'不是'std'的成员
 out * std :: stoi（std :: to_string（weights [i] ））; 
  

我已经读了一些类似的查询，答案是在-std = c ++ 11中添加， -std = c ++ 0x当编译 - 这两个解决方案都不工作。另一个解决方案建议在编译器版本中的错误，但它不是我使用的编译器我不认为。我在64x Apple Macbook Pro上使用g ++（GCC）5.0.0 20141005（实验版）。

感谢任何帮助。

解决方案

使用 stoi（）和 to_string（）在这部分代码是很奇怪，而且完全不必要。你可以简单地写

  int w = weights [i]  -  out * weights [i] 
 





---

要使用 std :: stoi（） 和 std :: to_string（） 您需要有正确的

  #include< string> ; 
  

语句和c ++ 11语言选项集（请参阅上述文档参考的链接） 。

I have some code, it's quite large so I'll just create a snapshot of it here:

    int l = 3;
    vector<int> weights;   

    void changeWeights(int out){
    for (int i = 0; i < weights.size(); i++){
        int w = std::stoi(std::to_string(weights[i])) -
        out*std::stoi(std::to_string(weights[i]));
        if (w < -l){
          w = -l;
        } else if(w > l){
            w = l;
        }
        weights.assign(i, w);
    }
}

I get errors on both the 'stoi' and 'to_string' function calls in the form of

Main.cpp:35:21: error: ‘stoi’ is not a member of ‘std’
         int w = std::stoi(std::to_string(weights[i])) -
                 ^
Main.cpp:35:31: error: ‘to_string’ is not a member of ‘std’
         int w = std::stoi(std::to_string(weights[i])) -
                           ^
Main.cpp:36:17: error: ‘stoi’ is not a member of ‘std’
         out*std::stoi(std::to_string(weights[i]));
             ^
Main.cpp:36:27: error: ‘to_string’ is not a member of ‘std’
         out*std::stoi(std::to_string(weights[i]));

I have read some similar queries whereby the answer was to add in -std=c++11 or -std=c++0x when compiling - both these solutions did not work. Another solution suggested a bug in the compiler version but it's not the compiler I am using I do not think. I am using g++ (GCC) 5.0.0 20141005 (experimental) version on a 64x Apple Macbook Pro.

Thanks for any help.

解决方案

Usage of stoi() and to_string() in this part of code is pretty weird, and completely unnecessary. You can simply write

int w = weights[i] - out * weights[i];

---

To use std::stoi() and std::to_string() you need to have a proper

#include <string>

statement, and the c++11 language options set (see the links to the documentation reference above).

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