共用方式為


unordered_map::bucket_count

取得 Bucket 的數目。

size_type bucket_count() const;

備註

成員函式來傳回包含目前數目。

範例

 

// std_tr1__unordered_map__unordered_map_bucket_count.cpp 
// compile with: /EHsc 
#include <unordered_map> 
#include <iostream> 
 
typedef std::unordered_map<char, int> Mymap; 
int main() 
    { 
    Mymap c1; 
 
    c1.insert(Mymap::value_type('a', 1)); 
    c1.insert(Mymap::value_type('b', 2)); 
    c1.insert(Mymap::value_type('c', 3)); 
 
// display contents " [c 3] [b 2] [a 1]" 
    for (Mymap::const_iterator it = c1.begin(); 
        it != c1.end(); ++it) 
        std::cout << " [" << it->first << ", " << it->second << "]"; 
    std::cout << std::endl; 
 
// inspect current parameters 
    std::cout << "bucket_count() == " << c1.bucket_count() << std::endl; 
    std::cout << "load_factor() == " << c1.load_factor() << std::endl; 
    std::cout << "max_bucket_count() == " 
        << c1.max_bucket_count() << std::endl; 
    std::cout << "max_load_factor() == " 
        << c1.max_load_factor() << std::endl; 
    std::cout << std::endl; 
 
// change max_load_factor and redisplay 
    c1.max_load_factor(0.10f); 
    std::cout << "bucket_count() == " << c1.bucket_count() << std::endl; 
    std::cout << "load_factor() == " << c1.load_factor() << std::endl; 
    std::cout << "max_bucket_count() == " 
        << c1.max_bucket_count() << std::endl; 
    std::cout << "max_load_factor() == " 
        << c1.max_load_factor() << std::endl; 
    std::cout << std::endl; 
 
// rehash and redisplay 
    c1.rehash(100); 
    std::cout << "bucket_count() == " << c1.bucket_count() << std::endl; 
    std::cout << "load_factor() == " << c1.load_factor() << std::endl; 
    std::cout << "max_bucket_count() == " 
        << c1.max_bucket_count() << std::endl; 
    std::cout << "max_load_factor() == " 
        << c1.max_load_factor() << std::endl; 
    std::cout << std::endl; 
 
    return (0); 
    } 
 
  

需求

標頭: <unordered_map>

命名空間: std

請參閱

參考

<unordered_map>

unordered_map 類別

unordered_map::bucket

unordered_map::bucket_size

unordered_map::load_factor

unordered_map::max_load_factor

其他資源

<unordered_map> 成員