调用具有结构体的所有实例的函数
问题描述:
我想调用一个具有所有结构体对象的函数。调用具有结构体的所有实例的函数
我需要一个函数,可以通过调用struct STRUCT_A来遍历结构对象A_1,A_2。代码底部的空函数'reset_all_structs(???)'。
示例代码:
#include <iostream>
struct STRUCT_A {
unsigned char number = 0;
bool bool_1 = 0;
bool bool_2 = 0;
} A_1, A_2; // Objects: maybe later A_3, ... , A_x
void print_to_terminal(STRUCT_A &STRUCT_NAME);
void set_bool_1(STRUCT_A &STRUCT_NAME);
void set_bool_2(STRUCT_A &STRUCT_NAME);
void reset_one_struct(STRUCT_A &STRUCT_NAME);
void reset_all_structs();
int main()
{
set_bool_1(A_1);
A_1.number = 111;
set_bool_2(A_2);
A_2.number = 222;
std::cout << "A_1:\n";
print_to_terminal(A_1);
std::cout << "\n";
std::cout << "A_2:\n";
print_to_terminal(A_2);
std::cout << "\n";
reset_one_struct(A_1); // <-- Reset one struct works, my question ist how to reset all structs with the type STRUCT_A?
std::cout << "A_1:\n";
print_to_terminal(A_1);
std::cout << "\n";
set_bool_2(A_1);
A_1.number = 234;
std::cout << "A_1:\n";
print_to_terminal(A_1);
std::cout << "\n";
// Here the question. ???
// reset_all_structs(STRUCT_A);
// I want to reset both A_1 and A_2 by calling the function reset_all_structs with all object of the struct "STRUCT_A" and loop through these. Is this possible
// I don't want to call a function like reset_all_struct(A_1, A_2) because later I will add more objects of struct STRUCT_A.
std::cout << "Reset A_1 and A_2\n";
std::cout << "A_1:\n";
print_to_terminal(A_1);
std::cout << "\n";
std::cout << "A_2:\n";
print_to_terminal(A_2);
std::cout << "\n";
return 0;
}
void print_to_terminal(STRUCT_A &STRUCT_NAME){
std::cout << "Number: " << (int)STRUCT_NAME.number << "\n";
std::cout << "bool_1: " << (int)STRUCT_NAME.bool_1 << "\n";
std::cout << "bool_2: " << (int)STRUCT_NAME.bool_2 << "\n";
return;
};
void set_bool_1(STRUCT_A &STRUCT_NAME){
STRUCT_NAME.bool_1 = 1;
STRUCT_NAME.bool_2 = 0;
return;
};
void set_bool_2(STRUCT_A &STRUCT_NAME){
STRUCT_NAME.bool_1 = 0;
STRUCT_NAME.bool_2 = 1;
return;
};
void reset_one_struct(STRUCT_A &STRUCT_NAME){
STRUCT_NAME.number = 0;
STRUCT_NAME.bool_1 = 0;
STRUCT_NAME.bool_2 = 0;
return;
};
void reset_all_structs(???){
// loop through all structs
return;
};
答
你可以把它们放在一个本地数组和循环遍历它,就像这样:
void reset_all_structs()
{
// This array can be created locally, and must capture by pointer
// arrays of references are illegal in C++.
STRUCT_A * structs[] = { &A_1, &A_2 };
for(int i = 0; i < sizeof(structs); i++)
{
reset_one_struct(*structs[i]);
}
}
顺便说一句,你标记你的问题C++,但是这看起来像C 。如果你是C++的新手,我建议你在你的结构中使用STRUCT_NAME的所有函数变成methods
。至少,将正式的STRUCT_NAME参数重命名为不会与结构名称本身或宏定义相冲突的东西。最后,我建议将你的结构实例收集到一个STL容器中,比如std::vector
,以使循环中的迭代和访问更简单。
答
改为使用array
或更好的vector
的structs
。
struct STRUCT_A {
unsigned char number = 0;
bool bool_1 = 0;
bool bool_2 = 0;
};
typedef struct STRUCT_A Data;
void set_bool_1(Data& data_i) {
data_i.bool_1 = 1;
}
void set_bool_2(Data& data_i) {
data_i.bool_1 = 1;
}
void reset_one_struct(Data& data_i) {
data_i.bool_1 = 0;
data_i.bool_2 = 0;
data_i.number = 0;
}
void reset_all_structs(std::vector<Data>& all_data) {
for(int i = 0; i < all_data.size(); ++i)
reset_one_struct(all_data[i]);
}
int main()
{
std::vector<Data> my_data(2);
set_bool_1(my_data[1]);
my_data[1].number = 111;
reset_one_struct(my_data[1]);
reset_all_structs(my_data);
答
语言本身不可能遍历相同类型的相同变量。
你可以做一些注册表的结构,然后遍历这个注册表。喜欢的东西:
struct STRUCT_A;
std::vector<STRUCT_A*> struct_A_registry;
struct STRUCT_A {
...
// constructor
STRUCT_A() { struct_A_registry.push_back(this); }
// destructor
~STRUCT_A() {
for (std::vector<STRUCT_A*>::iterator it = struct_A_registry.begin();
it != struct_A_registry.end(); ++it)
if (*it == this) {
struct_A_registry.erase(this);
break;
}
}
};
然后你reset_all_structs将只是
void reset_all_structs() {
for (std::vector<STRUCT_A*>::iterator it = struct_A_registry.begin();
it != struct_A_registry.end(); ++it)
reset_one_struct(**it);
}
或者,如果你在同一行的程序申报全部STRUCT_A变量,可以组织他们到一个数组,它会简单得多。
如果您的设计使用这些设施,您正在使用具有处理这种情况的设施的语言。阅读有关可用于操作一个或多个结构的容器(如std :: vector)的信息。 – 2013-05-04 13:50:20