Declare size of a vector inside class - c++

Question

I am trying to declare the size of a vector inside a class. I want the vector size equal to another attribute of this same class. Vector "table" is inside the class Hashtable. "bucket_count" is the intended size for the vector "table". the error given is "member is not a type name". Please let me know what another way I can declare the size of a vector inside the class. If not, then what is the way out? Thanks.
Please refer to the code below.
class HashTable {
public:
int bucket_count;
vector<list<string>> table(bucket_count);
//bool isEmpty(list<string> &cell) const;
int hashFunction(const string& s);
void insertItem(string value);
void removeItem(string value);
bool searchTable(string s);
void printTable();
void processQueries();
void processQuery(const Query& query);
};

Answer 1

I tried making a constructor which worked for me, but I am not sure why it worked.
Here is my code:
HashTable::HashTable(int bc)
: bucket_count(bc)
, table(bucket_count)
{}
In this, the bucket_count is initialized to bc in this constructor which is agreeable. But by that logic table should be initialized to bc. But that is not what happened. Instead the size of table vector got initialized (which is what I wanted).
If anyone could explain, why the constructor initialization worked this way it would be of great help.

Answer 2

The easiest solution would be
vector<list<string>> table{(size_t)bucket_count};

Answer 3

This depends largely on how, where and when you set the actual value of bucket_count. For example, you could set the size of the table vector in the initializer list of your class constructor. The following code lets you do this by setting the size in the constructor call, either by passing a size explicitly when you construct a class object, or by using a default value (42 in the code I've shown):
class HashTable {
public:
int bucket_count;
vector<list<string>> table;
HashTable(int bc = 42) : bucket_count(bc), table(bucket_count) { }
//...
Alternatively, if bucket_size is to remain constant and universal, you could make it a static constexpr member:
class HashTable {
public:
static constexpr auto bucket_count = 42;
vector<list<string>> table;
HashTable() : table(bucket_count) { }
//...