【C++17】string

【C++17】string_view用法

string_view

原型：

template<class CharT, class Traits = std::char_traits<CharT>>
 class basic_string_view;

1. 示例

 1 #include <iostream>
 2 #include <string_view>
 3 
 4 int main() {
 5     std::string_view sv("123456789", 5);
 6 
 7     for (auto it = sv.cbegin(); it != sv.cend(); ++it) {
 8         std::cout << *it << " ";
 9     }
10     std::cout << std::endl;
11 
12     std::cout << "size() = " << sv.size() << std::endl;
13     std::cout << "data() =  " << sv.data() << std::endl;
14     std::cout << "sv.front() = " << sv.front() << std::endl;
15     std::cout << "sv.back() =  " << sv.back() << std::endl;
16     return 0;
17 }

输出：

1 2 3 4 5 
size() = 5
data() =  123456789
sv.front() = 1
sv.back() =  5

#include <iostream>
#include <algorithm>
#include <string_view>
int main()
{
    std::string str = "   trim me";
    std::string_view v = str;
    v.remove_prefix(std::min(v.find_first_not_of(" "), v.size()));
    std::cout << "String: '" << str << "'
"
              << "View  : '" << v << "'
";
}