std::filesystem::path::root_directory

 

C++

编译器支持

自立实现与有宿主实现

语言

标准库

标准库标头

具名要求

功能特性测试宏 (C++20)

语言支持库

概念库 (C++20)

元编程库 (C++11)

诊断库

通用工具库

字符串库

容器库

迭代器库

范围库 (C++20)

算法库

数值库

本地化库

输入/输出库

文件系统库 (C++17)

正则表达式库 (C++11)

并发支持库 (C++11)

技术规范

符号索引

外部库

 

文件系统库

类
filesystem::path filesystem::filesystem_error filesystem::directory_entry filesystem::directory_iterator filesystem::recursive_directory_iterator filesystem::file_status	filesystem::space_info filesystem::file_type filesystem::perms filesystem::perm_options filesystem::copy_options filesystem::directory_options filesystem::file_time_type
函数
filesystem::absolute filesystem::canonicalfilesystem::weakly_canonical filesystem::relativefilesystem::proximate filesystem::copy filesystem::copy_file filesystem::copy_symlink filesystem::create_directory filesystem::create_directories filesystem::create_hard_link filesystem::create_symlink filesystem::create_directory_symlink filesystem::current_path	filesystem::exists filesystem::equivalent filesystem::file_size filesystem::hard_link_count filesystem::last_write_time filesystem::permissions filesystem::read_symlink filesystem::remove filesystem::remove_all filesystem::rename filesystem::resize_file filesystem::space filesystem::status filesystem::symlink_status filesystem::temp_directory_path
文件类型
filesystem::is_block_file filesystem::is_character_file filesystem::is_directory filesystem::is_empty filesystem::status_known	filesystem::is_fifo filesystem::is_other filesystem::is_regular_file filesystem::is_socket filesystem::is_symlink

 

std::filesystem::path

常量
path::native_formatpath::generic_formatpath::auto_format
成员函数
path::path path::~path path::operator= path::assign path::appendpath::operator /= path::concatpath::operator += path::clear path::make_preferred path::remove_filename path::replace_filename path::replace_extension path::swap path::compare path::beginpath::end	path::c_strpath::nativepath::operator string_type path::stringpath::u8stringpath::u16stringpath::u32stringpath::wstring path::generic_stringpath::generic_u8stringpath::generic_u16stringpath::generic_u32stringpath::generic_wstring path::lexically_normalpath::lexically_relativepath::lexically_proximate
路径分解
path::root_name path::root_directory path::root_path path::relative_path path::parent_path path::filename path::stem path::extension path::empty	path::has_root_pathpath::has_root_namepath::has_root_directorypath::has_relative_pathpath::has_parent_pathpath::has_filenamepath::has_stempath::has_extension path::is_absolutepath::is_relative
非成员函数
operator==operator!=operator<operator<=operator>operator>=operator<=> (C++20 前)(C++20 前)(C++20 前)(C++20 前)(C++20 前)(C++20)	operator/ operator<<operator>> swap(path) hash_value u8path
辅助类
hash

 

path root_directory() const;		(C++17 起)

返回通用格式路径的根目录。若路径（以通用格式）不包含根目录，则返回 path() 。

参数

（无）

返回值

路径的根目录。

异常

可能会抛出由实现定义的异常。

示例

运行此代码

#include <iostream>
#include <filesystem>
namespace fs = std::filesystem;
 
int main()
{
    fs::path p = fs::current_path();
 
    std::cout << "The current path " << p << " decomposes into:\n"
              << "root name " << p.root_name() << '\n'
              << "root directory " << p.root_directory() << '\n'
              << "relative path " << p.relative_path() << '\n';
}

可能的输出：

The current path "C:\Users\abcdef\Local Settings\temp" decomposes into:
root name "C:"
root directory "\"
relative path "Users\abcdef\Local Settings\temp"

参阅

root_name	若存在则返回路径的根名 (公开成员函数)
root_path	若存在则返回路径的根路径 (公开成员函数)