std::filesystem::u8path
From cppreference.com
< cpp | filesystem | path
Defined in header <filesystem>
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template< class Source > std::filesystem::path u8path( const Source& source ); |
(1) | (since C++17) (deprecated in C++20) |
template< class InputIt > std::filesystem::path u8path( InputIt first, InputIt last ); |
(2) | (since C++17) (deprecated in C++20) |
Constructs a path p
from a UTF-8 encoded sequence of chars or char8_ts(since C++20), supplied either as an std::string, or as std::string_view, or as a null-terminated multibyte string, or as a [first, last) iterator pair.
- If
path::value_type
is char and native encoding is UTF-8, constructs a path directly as if by path(source) or path(first, last). Note: this is the typical situation of a POSIX system that uses Unicode, such as Linux. - Otherwise, if
path::value_type
is wchar_t and native encoding is UTF-16 (this is the situation on Windows), or ifpath::value_type
is char16_t (native encoding guaranteed UTF-16) or char32_t (native encoding guaranteed UTF-32), then first converts the UTF-8 character sequence to a temporary stringtmp
of typepath::string_type
and then the new path is constructed as if by path(tmp). - Otherwise (for non-UTF-8 narrow character encodings and for non-UTF-16 wchar_t), first converts the UTF-8 character sequence to a temporary UTF-32-encoded string
tmp
of type std::u32string, and then the new path is constructed as if by path(tmp) (this path is taken on a POSIX system with a non-Unicode multibyte or single-byte encoded filesystem).
Contents |
[edit] Parameters
source | - | a UTF-8 encoded std::string, std::string_view, a pointer to a null-terminated multibyte string, or an input iterator with char value type that points to a null-terminated multibyte string |
first, last | - | pair of LegacyInputIterators that specify a UTF-8 encoded character sequence |
Type requirements | ||
-InputIt must meet the requirements of LegacyInputIterator.
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-The value type of Source or InputIt must be char or char8_t.(since C++20)
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[edit] Return value
The path constructed from the input string after conversion from UTF-8 to the filesystem's native character encoding.
[edit] Exceptions
May throw std::bad_alloc if memory allocation fails.
[edit] Notes
On systems where native path format differs from the generic path format (neither Windows nor POSIX systems are examples of such OSes), if the argument to this function is using generic format, it will be converted to native.
[edit] Example
Run this code
#include <cstdio> #ifdef _MSC_VER #include <fcntl.h> #include <io.h> #else #include <clocale> #include <locale> #endif #include <filesystem> #include <fstream> int main() { #ifdef _MSC_VER _setmode(_fileno(stderr), _O_WTEXT); #else std::setlocale(LC_ALL, ""); std::locale::global(std::locale("")); #endif std::filesystem::path p(u8"要らない.txt"); std::ofstream(p) << "File contents"; // Prior to LWG2676 uses operator string_type() // on MSVC, where string_type is wstring, only // works due to non-standard extension. // Post-LWG2676 uses new fstream constructors // Native string representation can be used with OS-specific APIs #ifdef _MSC_VER if (std::FILE* f = _wfopen(p.c_str(), L"r")) #else if (std::FILE* f = std::fopen(p.c_str(), "r")) #endif { for (int ch; (ch = fgetc(f)) != EOF; std::putchar(ch)) {} std::fclose(f); } std::filesystem::remove(p); }
Possible output:
File contents
[edit] See also
(C++17) |
represents a path (class) |