hash_set::empty (STL/CLR)

测试元素是否存在。

    bool empty();

备注

由一个空序列控制，则成员函数返回 true。 它等效于hash_set::size (STL/CLR)() == 0。 使用它来测试 hash_set 是否为空。

示例

// cliext_hash_set_empty.cpp 
// compile with: /clr 
#include <cliext/hash_set> 
 
typedef cliext::hash_set<wchar_t> Myhash_set; 
int main() 
    { 
    Myhash_set c1; 
    c1.insert(L'a'); 
    c1.insert(L'b'); 
    c1.insert(L'c'); 
 
// display initial contents " a b c" 
    for each (wchar_t elem in c1) 
        System::Console::Write(" {0}", elem); 
    System::Console::WriteLine(); 
    System::Console::WriteLine("size() = {0}", c1.size()); 
    System::Console::WriteLine("empty() = {0}", c1.empty()); 
 
// clear the container and reinspect 
    c1.clear(); 
    System::Console::WriteLine("size() = {0}", c1.size()); 
    System::Console::WriteLine("empty() = {0}", c1.empty()); 
    return (0); 
    } 
 

要求

标头: <cliext/hash_set>

命名空间: cliext

请参见

参考

hash_set (STL/CLR)

hash_set::size (STL/CLR)