hash_map : : réchauffé (STL/CLR)

Article
06/10/2015

Régénère la table de hachage.

    void rehash();

Notes

La fonction membre reconstruit la table de hachage, ce qui garantit hash_map : : load_factor (STL/CLR)() <= hash_map : : max_load_factor (STL/CLR). Sinon, la table de hachage augmente sa taille de la manière nécessaire après une insertion. (Cela ne diminue jamais automatiquement de taille.) Vous l'utilisez pour ajuster la taille de la table de hachage.

Exemple

// cliext_hash_map_rehash.cpp 
// compile with: /clr 
#include <cliext/hash_map> 
 
typedef cliext::hash_map<wchar_t, int> Myhash_map; 
int main() 
    { 
    Myhash_map c1 = gcnew Myhash_map; 
    c1.insert(Myhash_map::make_value(L'a', 1)); 
    c1.insert(Myhash_map::make_value(L'b', 2)); 
    c1.insert(Myhash_map::make_value(L'c', 3)); 
 
// display contents " [a 1] [b 2] [c 3]" 
    for each (Myhash_map::value_type elem in c1) 
        System::Console::Write(" [{0} {1}]", elem->first, elem->second); 
    System::Console::WriteLine(); 
 
// inspect current parameters 
    System::Console::WriteLine("bucket_count() = {0}", c1.bucket_count()); 
    System::Console::WriteLine("load_factor() = {0}", c1.load_factor()); 
    System::Console::WriteLine("max_load_factor() = {0}", 
        c1.max_load_factor()); 
    System::Console::WriteLine(); 
 
// change max_load_factor and redisplay 
    c1.max_load_factor(0.25f); 
    System::Console::WriteLine("bucket_count() = {0}", c1.bucket_count()); 
    System::Console::WriteLine("load_factor() = {0}", c1.load_factor()); 
    System::Console::WriteLine("max_load_factor() = {0}", 
        c1.max_load_factor()); 
    System::Console::WriteLine(); 
 
// rehash and redisplay 
    c1.rehash(100); 
    System::Console::WriteLine("bucket_count() = {0}", c1.bucket_count()); 
    System::Console::WriteLine("load_factor() = {0}", c1.load_factor()); 
    System::Console::WriteLine("max_load_factor() = {0}", 
        c1.max_load_factor()); 
    return (0); 
    }