basic_string::difference_type

提供引用同一字符串中元素的两个迭代器之间的差异的类型。

typedef typename allocator_type::difference_type difference_type;

备注

带符号整数类型描述可以表示任何两个元素间的差异。地址控件序列的对象。

对于 字符串类型，它等效于 ptrdiff_t等效。

示例

// basic_string_diff_type.cpp
// compile with: /EHsc
#include <string>
#include <iostream>

int main( ) 
{
   using namespace std;
   string str1 ( "quintillion" );
   cout << "The original string str1 is: " << str1 << endl;
   basic_string <char>::size_type indexChFi, indexChLi;

   indexChFi = str1.find_first_of ( "i" );
   indexChLi = str1.find_last_of ( "i" );
   basic_string<char>::difference_type diffi = indexChLi - indexChFi;

   cout << "The first character i is at position: "
        << indexChFi << "." << endl;
   cout << "The last character i is at position: "
        << indexChLi << "." << endl;
   cout << "The difference is: " << diffi << "." << endl;
}

要求

标头：< 字符串>

命名空间: std

请参见

参考

basic_string 类