c++ - 在结构中分配数组字段

Question

最近我开始研究 C++ 代码，我试图与一个外部库进行通信，该库具有如下定义的结构

struct StudentsInformation {
    int student_count[10];
    double total_marks[10];
    double section_marks_average;
    double class_marks_average;
};

我试图在一个单独的类中为这个结构创建一个对象，如下所示

int count[10] = {1, 2, 3, 4, 5, 1, 2, 3, 4, 5}; 
double marks[10] = {10.0, 20.0, 30.0, 40.0, 50.0, 10.0, 20.0, 30.0, 40.0, 50.0};

StudentsInformation stuInfo = { count, marks, 68.8, 56.7 };

编译它会出现以下错误

Cannot initialize an array element of type 'int' with an lvalue oftype 'int [10]'

不确定我做错了什么。

Answer 1

这应该可以在 C 和/或 C++ 中正常编译:

#include <stdio.h>

struct StudentsInformation {
    int student_count[10];
    double total_marks[10];
    double section_marks_average;
    double class_marks_average;
};

int main(int argc, char *argv[]) {
  struct StudentsInformation si = {
    {1, 2, 3, 4, 5, 1, 2, 3, 4, 5},
    {10.0, 20.0, 30.0, 40.0, 50.0, 10.0, 20.0, 30.0, 40.0, 50.0},
    68.8, 56.7
  };

  return 0;
}

错误信息的关键部分是“cannot convert an lvalue”:

https://en.cppreference.com/w/cpp/language/value_category

lvalue:

the name of a variable, a function, a template parameter object (sinceC++20), or a data member, regardless of type, such as std::cin orstd::endl. Even if the variable's type is rvalue reference, theexpression consisting of its name is an lvalue expression;