Is it correct method to have map within struct and then having array of structure.
struct node { //struct node
std::map<int ,int> mymap;//stl map within struct
};
struct node n[10]; //array of struct node
Then how to initialise n and refer to map within it? How to have iterator to map within struct that is mymap? any best way?
Bad or good idea is opinion-based. However, it is not wrong.
std::map does not need to be initialized. The default constructor will do it for you.
How to access your map ?
for(size_t i=0;i<10;++i){
n[i].mymap//.something
}
struct node n[10];
Creates an array of 10 nodes that are default initialized. Since std::map has a default constructor each node in n will have the map default constructed.
To access the map you just use
n[some_valid_index].mymap//.some_member_function;
Remember that arrays are 0 index based so some_valid_index needs to be in the range of [0, 9]
auto it = n[some_valid_index].mymap.begin();There is an example static initialisztion:
node n[3] = {
{
{ {1,2}, {3,4} }
},
{
{ {1,2}, {3,4} }
},
{
{ {1,2}, {3,4} }
}
};
remove "struct" before n declaration. and about accessing map elements like this:
n[1].mymap[1] // = 2
n[2].mymap[3] // = 4
need to specify modern c++ language standart, for gcc command line will be like this:
g++ -std=c++0x main.cpp
mymapis default construct so is empty (it is valid).