std::filesystem::path::append, std::filesystem::path::operator/=
From cppreference.com
< cpp | filesystem | path
path& operator/=(const path& p); |
(1) | (since C++17) |
template< class Source > path& operator/=( const Source& source ); |
(2) | (since C++17) |
template< class Source > path& append( const Source& source ); |
(3) | (since C++17) |
template< class InputIt > path& append( InputIt first, InputIt last ); |
(4) | (since C++17) |
1) If p.is_absolute() || (p.has_root_name() && p.root_name() != root_name()), then replaces the current path with p as if by operator=(p) and finishes.
* Otherwise, if p.has_root_directory(), then removes any root directory and the entire relative path from the generic format pathname of *this
* Otherwise, if has_filename() || (!has_root_directory() && is_absolute()), then appends
path::preferred_separator
to the generic format of *this * Either way, then appends the native format pathname of
p
, omitting any root-name from its generic format, to the native format of *this.// where "//host" is a root-name path("//host") / "foo" // the result is "//host/foo" (appends with separator) path("//host/") / "foo" // the result is also "//host/foo" (appends without separator) // On POSIX, path("foo") / "" // the result is "foo/" (appends) path("foo") / "/bar"; // the result is "/bar" (replaces) // On Windows, path("foo") / "C:/bar"; // the result is "C:/bar" (replaces) path("foo") / "C:"; // the result is "C:" (replaces) path("C:") / ""; // the result is "C:" (appends, without separator) path("C:foo") / "/bar"; // yields "C:/bar" (removes relative path, then appends) path("C:foo") / "C:bar"; // yields "C:foo/bar" (appends, omitting p's root-name)
2,3) Same as (1), but accepts any std::basic_string, std::basic_string_view, null-terminated multicharacter string, or an input iterator pointing to a null-terminated multicharacter sequence. Equivalent to return operator/=(path(source));.
4) Same as (1), but accepts any iterator pair that designates a multicharacter string. Equivalent to return operator/=(path(first, last));
Parameters
p | - | pathname to append |
source | - | std::basic_string, std::basic_string_view, null-terminated multicharacter string, or an input iterator pointing to a null-terminated multicharacter sequence, which represents a path name (either in portable or in native format) |
first, last | - | pair of LegacyInputIterators that specify a multicharacter sequence that represents a path name |
Type requirements | ||
-InputIt must meet the requirements of LegacyInputIterator.
| ||
-The value type of InputIt must be one of the encoded character types (char, wchar_t, char16_t and char32_t)
|
Return value
*this
Exceptions
May throw std::bad_alloc if memory allocation fails.
Notes
These functions effectively yield an approximation of the meaning of the argument path p
in an environment where *this
is the starting directory.
Example
Run this code
#include <iostream> #include <filesystem> namespace fs = std::filesystem; int main() { fs::path p1 = "C:"; p1 /= "Users"; // does not insert a separator std::cout << "\"C:\" / \"Users\" == " << p1 << '\n'; p1 /= "batman"; // inserts fs::path::preferred_separator, '\' on Windows std::cout << "\"C:\" / \"Users\" / \"batman\" == " << p1 << '\n'; }
Possible output:
"C:" / "Users" == "C:Users" "C:" / "Users" / "batman" == "C:Users\\batman"
See also
concatenates two paths without introducing a directory separator (public member function) | |
concatenates two paths with a directory separator (function) |