unordered_set::difference_type
帶正負號的距離,兩個元素之間的型別。
typedef T3 difference_type;
備註
帶正負號的整數型別描述的物件,可以表示任何兩個項目在受控制序列中的地址之間的差異。 描述實作定義的型別同義資料表視為T3。
範例
// std_tr1__unordered_set__unordered_set_difference_type.cpp
// compile with: /EHsc
#include <unordered_set>
#include <iostream>
typedef std::unordered_set<char> Myset;
int main()
{
Myset c1;
c1.insert('a');
c1.insert('b');
c1.insert('c');
// display contents " [c] [b] [a]"
for (Myset::const_iterator it = c1.begin();
it != c1.end(); ++it)
std::cout << " [" << *it << "]";
std::cout << std::endl;
// compute positive difference
Myset::difference_type diff = 0;
for (Myset::const_iterator it = c1.begin();
it != c1.end(); ++it)
++diff;
std::cout << "end()-begin() == " << diff << std::endl;
// compute negative difference
diff = 0;
for (Myset::const_iterator it = c1.end();
it != c1.begin(); --it)
--diff;
std::cout << "begin()-end() == " << diff << std::endl;
return (0);
}
需求
標頭: <unordered_set>
Namespace: 標準