path() noexcept;
path(const path& p);
path(path&& p) noexcept;
Effects: Constructs an object of class path having the same pathname in the native and generic formats, respectively, as the original value of p. In the second form, p is left in a valid but unspecified state.
path(string_type&& source, format fmt = auto_format);
Effects: Constructs an object of class path for which the pathname in the detected-format of source has the original value of source ([fs.path.fmt.cvt]), converting format if required ([fs.path.fmt.cvt]). source is left in a valid but unspecified state.
template <class Source>
path(const Source& source, format fmt = auto_format);
template <class InputIterator>
path(InputIterator first, InputIterator last, format fmt = auto_format);
Effects: Let s be the effective range of source ([fs.path.req]) or the range [first, last), with the encoding converted if required ([fs.path.cvt]). Finds the detected-format of s ([fs.path.fmt.cvt]) and constructs an object of class path for which the pathname in that format is s.
template <class Source>
path(const Source& source, const locale& loc, format fmt = auto_format);
template <class InputIterator>
path(InputIterator first, InputIterator last, const locale& loc, format fmt = auto_format);
Effects: Let s be the effective range of source or the range [first, last), after converting the encoding as follows:
If value_type is wchar_t, converts to the native wide encoding ([fs.def.native.encode]) using the codecvt<wchar_t, char, mbstate_t> facet of loc.
Otherwise a conversion is performed using the codecvt<wchar_t, char, mbstate_t> facet of loc, and then a second conversion to the current narrow encoding.
Finds the detected-format of s ([fs.path.fmt.cvt]) and constructs an object of class path for which the pathname in that format is s.
[ Example: A string is to be read from a database that is encoded in ISO/IEC 8859-1, and used to create a directory:
namespace fs = std::filesystem; std::string latin1_string = read_latin1_data(); codecvt_8859_1<wchar_t> latin1_facet; std::locale latin1_locale(std::locale(), latin1_facet); fs::create_directory(fs::path(latin1_string, latin1_locale));
For POSIX-based operating systems, the path is constructed by first using latin1_facet to convert ISO/IEC 8859-1 encoded latin1_string to a wide character string in the native wide encoding ([fs.def.native.encode]). The resulting wide string is then converted to a narrow character pathname string in the current native narrow encoding. If the native wide encoding is UTF-16 or UTF-32, and the current native narrow encoding is UTF-8, all of the characters in the ISO/IEC 8859-1 character set will be converted to their Unicode representation, but for other native narrow encodings some characters may have no representation.
For Windows-based operating systems, the path is constructed by using latin1_facet to convert ISO/IEC 8859-1 encoded latin1_string to a UTF-16 encoded wide character pathname string. All of the characters in the ISO/IEC 8859-1 character set will be converted to their Unicode representation. — end example ]
path& operator=(const path& p);
Effects: If *this and p are the same object, has no effect. Otherwise, sets both respective pathnames of *this to the respective pathnames of p.
path& operator=(path&& p) noexcept;
Effects: If *this and p are the same object, has no effect. Otherwise, sets both respective pathnames of *this to the respective pathnames of p. p is left in a valid but unspecified state. [ Note: A valid implementation is swap(p). — end note ]
path& operator=(string_type&& source);
path& assign(string_type&& source);
Effects: Sets the pathname in the detected-format of source to the original value of source. source is left in a valid but unspecified state.
template <class Source>
path& operator=(const Source& source);
template <class Source>
path& assign(const Source& source);
template <class InputIterator>
path& assign(InputIterator first, InputIterator last);
Effects: Let s be the effective range of source ([fs.path.req]) or the range [first, last), with the encoding converted if required ([fs.path.cvt]). Finds the detected-format of s ([fs.path.fmt.cvt]) and sets the pathname in that format to s.
The append operations use operator/= to denote their semantic effect of appending preferred-separator when needed.
path& operator/=(const path& p);
Effects: If p.is_absolute() || (p.has_root_name() && p.root_name() != root_name()), then operator=(p).
Otherwise, modifies *this as if by these steps:
If p.has_root_directory(), then removes any root directory and relative path from the generic format pathname. Otherwise, if !has_root_directory() && is_absolute() is true or if has_filename() is true, then appends path::preferred_separator to the generic format pathname.
Then appends the native format pathname of p, omitting any root-name from its generic format pathname, to the native format pathname.
[ Example: Even if //host is interpreted as a root-name, both of the paths path("//host")/"foo" and path("//host/")/"foo" equal "//host/foo".
Expression examples:
// On POSIX, path("foo") / ""; // yields "foo/" path("foo") / "/bar"; // yields "/bar" // On Windows, backslashes replace slashes in the above yields // On Windows, path("foo") / "c:/bar"; // yields "c:/bar" path("foo") / "c:"; // yields "c:" path("c:") / ""; // yields "c:" path("c:foo") / "/bar"; // yields "c:/bar" path("c:foo") / "c:bar"; // yields "c:foo/bar"
— end example ]
template <class Source>
path& operator/=(const Source& source);
template <class Source>
path& append(const Source& source);
template <class InputIterator>
path& append(InputIterator first, InputIterator last);
path& operator+=(const path& x);
path& operator+=(const string_type& x);
path& operator+=(basic_string_view<value_type> x);
path& operator+=(const value_type* x);
path& operator+=(value_type x);
template <class Source>
path& operator+=(const Source& x);
template <class EcharT>
path& operator+=(EcharT x);
template <class Source>
path& concat(const Source& x);
Effects: Appends path(x).native() to the pathname in the native format. [ Note: This directly manipulates the value of native() and may not be portable between operating systems. — end note ]
template <class InputIterator>
path& concat(InputIterator first, InputIterator last);
void clear() noexcept;
path& make_preferred();
Effects: Each directory-separator of the pathname in the generic format is converted to preferred-separator.
[ Example:
path p("foo/bar");
std::cout << p << '\n';
p.make_preferred();
std::cout << p << '\n';On an operating system where preferred-separator is a slash, the output is:
"foo/bar" "foo/bar"
On an operating system where preferred-separator is a backslash, the output is:
"foo/bar" "foo\bar"
— end example ]
path& remove_filename();
[ Example:
path("foo/bar").remove_filename(); // yields "foo/"
path("foo/").remove_filename(); // yields "foo/"
path("/foo").remove_filename(); // yields "/"
path("/").remove_filename(); // yields "/"
— end example ]
path& replace_filename(const path& replacement);
[ Example:
path("/foo").replace_filename("bar"); // yields "/bar" on POSIX
path("/").replace_filename("bar"); // yields "/bar" on POSIX
— end example ]
path& replace_extension(const path& replacement = path());
Effects:
Any existing extension()([fs.path.decompose]) is removed from the pathname in the generic format, then
If replacement is not empty and does not begin with a dot character, a dot character is appended to the pathname in the generic format, then
operator+=(replacement);.
void swap(path& rhs) noexcept;
const string_type& native() const noexcept;
const value_type* c_str() const noexcept;
operator string_type() const;
[ Note: Conversion to string_type is provided so that an object of class path can be given as an argument to existing standard library file stream constructors and open functions. — end note ]
template <class EcharT, class traits = char_traits<EcharT>,
class Allocator = allocator<EcharT>>
basic_string<EcharT, traits, Allocator>
string(const Allocator& a = Allocator()) const;
Remarks: All memory allocation, including for the return value, shall be performed by a. Conversion, if any, is specified by [fs.path.cvt].
std::string string() const;
std::wstring wstring() const;
std::string u8string() const;
std::u16string u16string() const;
std::u32string u32string() const;
Remarks: Conversion, if any, is performed as specified by [fs.path.cvt]. The encoding of the string returned by u8string() is always UTF-8.
Generic format observer functions return strings formatted according to the generic pathname format. A single slash ('/') character is used as the directory-separator.
[ Example: On an operating system that uses backslash as its preferred-separator,
path("foo\\bar").generic_string()returns "foo/bar". — end example ]
template <class EcharT, class traits = char_traits<EcharT>,
class Allocator = allocator<EcharT>>
basic_string<EcharT, traits, Allocator>
generic_string(const Allocator& a = Allocator()) const;
Remarks: All memory allocation, including for the return value, shall be performed by a. Conversion, if any, is specified by [fs.path.cvt].
std::string generic_string() const;
std::wstring generic_wstring() const;
std::string generic_u8string() const;
std::u16string generic_u16string() const;
std::u32string generic_u32string() const;
Remarks: Conversion, if any, is specified by [fs.path.cvt]. The encoding of the string returned by generic_u8string() is always UTF-8.
int compare(const path& p) const noexcept;
Returns:
A value less than 0, if native() for the elements of *this are lexicographically less than native() for the elements of p; otherwise,
a value greater than 0, if native() for the elements of *this are lexicographically greater than native() for the elements of p; otherwise,
0.
Remarks: The elements are determined as if by iteration over the half-open range [begin(), end()) for *this and p.
int compare(const string_type& s) const
int compare(basic_string_view<value_type> s) const;
int compare(const value_type* s) const
path root_name() const;
path root_directory() const;
Returns: root-directory, if the pathname in the generic format includes root-directory, otherwise path().
path root_path() const;
path relative_path() const;
path parent_path() const;
Returns: *this if !has_relative_path(), otherwise a path whose generic format pathname is the longest prefix of the generic format pathname of *this that produces one fewer element in its iteration.
path filename() const;
[ Example:
path("/foo/bar.txt").filename(); // yields "bar.txt"
path("/foo/bar").filename(); // yields "bar"
path("/foo/bar/").filename(); // yields ""
path("/").filename(); // yields ""
path("//host").filename(); // yields ""
path(".").filename(); // yields "."
path("..").filename(); // yields ".."
— end example ]
path stem() const;
[ Example:
std::cout << path("/foo/bar.txt").stem(); // outputs "bar"
path p = "foo.bar.baz.tar";
for (; !p.extension().empty(); p = p.stem())
std::cout << p.extension() << '\n';
// outputs: .tar
// .baz
// .bar
— end example ]
path extension() const;
Returns: a path whose pathname in the generic format is the suffix of filename() not included in stem().
[ Example:
path("/foo/bar.txt").extension(); // yields ".txt" and stem() is "bar"
path("/foo/bar").extension(); // yields "" and stem() is "bar"
path("/foo/.profile").extension(); // yields "" and stem() is ".profile"
path(".bar").extension(); // yields "" and stem() is ".bar"
path("..bar").extension(); // yields ".bar" and stem() is "."
— end example ]
[ Note: The period is included in the return value so that it is possible to distinguish between no extension and an empty extension. — end note ]
bool empty() const noexcept;
bool has_root_path() const;
bool has_root_name() const;
bool has_root_directory() const;
bool has_relative_path() const;
bool has_parent_path() const;
bool has_filename() const;
bool has_stem() const;
bool has_extension() const;
bool is_absolute() const;
Returns: true if the pathname in the native format contains an absolute path, else false.
[ Example: path("/").is_absolute() is true for POSIX-based operating systems, and false for Windows-based operating systems. — end example ]
bool is_relative() const;
path lexically_normal() const;
Returns: A path whose pathname in the generic format is the normal form of the pathname in the generic format of *this.
[ Example:
assert(path("foo/./bar/..").lexically_normal() == "foo/");
assert(path("foo/.///bar/../").lexically_normal() == "foo/");The above assertions will succeed. On Windows, the returned path's directory-separator characters will be backslashes rather than slashes, but that does not affect path equality. — end example ]
path lexically_relative(const path& base) const;
Effects: If root_name() != base.root_name() is true or is_absolute() != base.is_absolute() is true or !has_root_directory() && base.has_root_directory() is true, returns path(). Determines the first mismatched element of *this and base as if by:
auto [a, b] = mismatch(begin(), end(), base.begin(), base.end());
Then,
if a == end() and b == base.end(), returns path("."); otherwise
let n be the number of filename elements in [b, base.end()) that are not dot or dot-dot minus the number that are dot-dot. If n<0, returns path(); otherwise
returns an object of class path that is default-constructed, followed by
application of operator/=(path("..")) n times, and then
application of operator/= for each element in [a, end()).
[ Example:
assert(path("/a/d").lexically_relative("/a/b/c") == "../../d");
assert(path("/a/b/c").lexically_relative("/a/d") == "../b/c");
assert(path("a/b/c").lexically_relative("a") == "b/c");
assert(path("a/b/c").lexically_relative("a/b/c/x/y") == "../..");
assert(path("a/b/c").lexically_relative("a/b/c") == ".");
assert(path("a/b").lexically_relative("c/d") == "../../a/b");The above assertions will succeed. On Windows, the returned path's directory-separator characters will be backslashes rather than slashes, but that does not affect path equality. — end example ]
[ Note: If symlink following semantics are desired, use the operational function relative(). — end note ]
[ Note: If normalization is needed to ensure consistent matching of elements, apply lexically_normal() to *this, base, or both. — end note ]
path lexically_proximate(const path& base) const;
Returns: If the value of lexically_relative(base) is not an empty path, return it. Otherwise return *this.
[ Note: If symlink following semantics are desired, use the operational function proximate(). — end note ]
[ Note: If normalization is needed to ensure consistent matching of elements, apply lexically_normal() to *this, base, or both. — end note ]