std::basic_string<CharT,Traits,Allocator>::operator basic_string_view

 

C++

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功能测试宏 (C++20)

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类

basic_string

basic_string_view (C++17)

char_traits

 

std::basic_string

成员函数 basic_string::basic_string basic_string::~basic_string basic_string::operator= basic_string::assign basic_string::assign_range (C++23) basic_string::get_allocator 元素访问 basic_string::at basic_string::operator[] basic_string::front (DR*) basic_string::back (DR*) basic_string::data basic_string::c_str basic_string::operator  basic_string_view (C++17) 迭代器 basic_string::beginbasic_string::cbegin (C++11) basic_string::endbasic_string::cend (C++11) basic_string::rbeginbasic_string::crbegin (C++11) basic_string::rendbasic_string::crend (C++11) 容量 basic_string::empty basic_string::sizebasic_string::length basic_string::max_size basic_string::reserve basic_string::capacity basic_string::shrink_to_fit (DR*) 修改器 basic_string::clear basic_string::insert basic_string::insert_range (C++23) basic_string::erase basic_string::push_back basic_string::pop_back (DR*) basic_string::append basic_string::append_range (C++23) basic_string::operator+= basic_string::replace basic_string::replace_with_range (C++23) basic_string::copy basic_string::resize basic_string::resize_and_overwrite (C++23)   basic_string::swap

搜索 basic_string::find basic_string::rfind basic_string::find_first_of basic_string::find_first_not_of basic_string::find_last_of basic_string::find_last_not_of 操作 basic_string::compare basic_string::starts_with (C++20) basic_string::ends_with (C++20) basic_string::contains (C++23) basic_string::substr 常量 basic_string::npos 非成员函数 operator+ swap(std::basic_string) erase(std::basic_string)erase_if(std::basic_string) (C++20)(C++20) I/O operator<<operator>> getline 比较 operator==operator!=operator<operator>operator<=operator>=operator<=> (直到 C++20)(直到 C++20)(直到 C++20)(直到 C++20)(直到 C++20)(C++20) 数值转换 stoistolstoll (C++11)(C++11)(C++11) stoulstoull (C++11)(C++11) stofstodstold (C++11)(C++11)(C++11) to_string (C++11) to_wstring (C++11) 文字 operator""s (C++14) 辅助类 hash<std::basic_string> (C++11) 推导指南 (C++17)

 

operator std::basic_string_view<CharT, Traits>() const noexcept;		(自 C++17) (自 C++20 起为 constexpr)

返回一个 std::basic_string_view，构造方式类似于 std::basic_string_view<CharT, Traits>(data(), size()).

参数

(无)

返回值

一个表示字符串所有内容的字符串视图。

备注

程序员有责任确保生成的字符串视图不会超出字符串的生命周期。

std::string get_string();
int f(std::string_view sv);
 
int x = f(get_string()); // OK
std::string_view sv = get_string(); // Bad: holds a dangling pointer

示例

运行此代码

#include <iostream>
#include <string>
#include <string_view>
 
void show_wstring_size(std::wstring_view wcstr_v)
{
    std::cout << wcstr_v.size() << " code points\n";
}
 
int main()
{
    std::string cppstr = "ラーメン";   // narrow string
    std::wstring wcstr = L"ラーメン";  // wide string
 
    // Implicit conversion from string to string_view
    // via std::string::operator string_view:
    std::string_view cppstr_v = cppstr;
 
    std::cout << cppstr_v << '\n'
              << cppstr_v.size() << " code units\n";
 
    // Implicit conversion from wstring to wstring_view
    // via std::wstring::operator wstring_view:
    show_wstring_size(wcstr);
}

输出

ラーメン
12 code units
4 code points

另请参阅

(构造函数)

构造一个 basic_string_view (std::basic_string_view<CharT,Traits> 的公共成员函数)