In v3, equivaluent would successfully return false if one of the paths
existed and the other one didn't. v4 now fails in this case, similar
to std::filesystem.
std::filesystem::path::generic_string mandates that the returned string
uses *single* forward slashes for directory separators, which means
any duplicates must be removed. Boost.Filesystem now follows this definition,
and also documents that forward slashes are used for directory separators.
Additionally, since only directory separators are supposed to be affected,
in v4 avoid converting any slashes that are part of the path root name. This
is the case on Windows with UNC paths and Windows-specific path prefixes.
Keep v3 behavior unchanged for backward compatibility.
Closes https://github.com/boostorg/filesystem/issues/299.
This commit changes behavior of directory_entry constructors and modifiers
that change the stored path in v4: the methods will now automatically query
the filesystem for the file status instead of leaving the cached data
default-initialized. This means that the paths passed to directory_entry
must be valid, otherwise an error will be returned. Filesystem querying
is implemented in the new directory_entry::refresh methods.
The constructors and modifiers that accepted file_status arguments are
now removed in v4. The cached file statuses are an implementation detail,
and eventually we may want to add more cached data, as we add more observers
to directory_entry.
Also added a few file type observers to directory_entry. These observers
allow to avoid querying the filesystem if the full file status is not cached
but the file type is (i.e. when permissions are not cached). This is the case
with readdir-based implementation of directory_iterator, if the underlying
C library supports dirent::d_type field.
recursive_directory_iterator has been updated to use the added file type
observers instead of querying the full status. This may improve performance
of directory iteration.
Closes https://github.com/boostorg/filesystem/issues/288.
v4 remove_filename works similar to std::filesystem, i.e. preserves
the trailing directory separator after removing the filename.
v3 remove_filename works as before. Its behavior is also useful in
v4, so added a new method remove_filename_and_trailing_separators
with the same behavior.
Also added replace_filename that was previously missing.
remove_filename discrepancy from std::filesystem was reported in:
https://github.com/boostorg/filesystem/issues/271
Users are advised to use string types and iterators instead of containers
to construct/assign/append to paths.
In v4, the support for containers is removed.
In v4 path::lexically_normal, don't generate a trailing dot element if the
original path ends with a directory separator or dot. Also omit the trailing
directory separator the normalized path ends with a dot-dot element.
Additionally, convert directory separators to preferred separators in
root name on Windows (in v3 and v4). This may be significant for UNC paths.
Appending an absolute path now results in assigning the path, as
specified in C++17. This change is made for consistency with C++
and other languages that implement path manipulation (e.g. Python).
In Boost.Filesystem v3 path appending mostly worked as a slight upgrade
of concatenation, where appending would only add directory separators
when necessary, but not consider semantics of the root name and root
directory of the appended paths. This would work well for relative paths,
but produce unexpected results for paths with root names.
In v4, we now implement appending that is aware of root name and directory
of the appendedn paths. This means that appending a path with a root name
and/or directory no longer concatenates the paths, but rather rebases the
appended path on top of the source path. In particular, if the appended path
has a root name different from the source path, the append operation will
act as assignment.
This is closer to C++20 std::filesystem but not exactly the same. The
difference is for the case when the appended path is absolute. The C++20
spec requires assignment in this case, Boost.Filesystem v4 deliberately
omits this check. This is to ensure the correct result for UNC paths on
POSIX systems, where "//net/foo" / "/bar" is expected to produce "//net/bar",
not "/bar".
As part of this work, refactored path constructors and operators for more
optimal implementation and reducing the number of overloads.
Closes https://github.com/boostorg/filesystem/issues/214.
When the path ends with a non-root directory separator, no longer
produce a trailing dot element (filename). Instead, return an empty
path.
This affects not only path iterators and path::filename, but also any
other APIs that rely on them.
Closes https://github.com/boostorg/filesystem/issues/193.
Boost.Filesystem v4 will contain breaking changes from v3 that are required
for better compatibility with C++17 std::filesystem. It will also remove
the deprecated features of v3.
Updated docs to reflect the differences between v3 and v4. Updated tests
to verify both v3 and v4 where the differences are present.
