30 Input/output library [input.output]

30.10 File systems [filesystems]

30.10.9 Class filesystem_­error [fs.class.filesystem_error]

namespace std::filesystem {
  class filesystem_error : public system_error {
  public:
    filesystem_error(const string& what_arg, error_code ec);
    filesystem_error(const string& what_arg,
                     const path& p1, error_code ec);
    filesystem_error(const string& what_arg,
                     const path& p1, const path& p2, error_code ec);

    const path& path1() const noexcept;
    const path& path2() const noexcept;
    const char* what() const noexcept override;
  };
}
1
#
The class filesystem_­error defines the type of objects thrown as exceptions to report file system errors from functions described in this subclause.

30.10.9.1 filesystem_­error members [filesystem_error.members]

1
#
Constructors are provided that store zero, one, or two paths associated with an error.
filesystem_error(const string& what_arg, error_code ec);
2
#
Postconditions: The postconditions of this function are indicated in Table 114.
Table 114 — filesystem_­error(const string&, error_­code) effects
Expression
Value
runtime_­error​::​what()
what_­arg.c_­str()
code()
ec
path1().empty()
true
path2().empty()
true
filesystem_error(const string& what_arg, const path& p1, error_code ec);
3
#
Postconditions: The postconditions of this function are indicated in Table 115.
Table 115 — filesystem_­error(const string&, const path&, error_­code) effects
Expression
Value
runtime_­error​::​what()
what_­arg.c_­str()
code()
ec
path1()
Reference to stored copy of p1
path2().empty()
true
filesystem_error(const string& what_arg, const path& p1, const path& p2, error_code ec);
4
#
Postconditions: The postconditions of this function are indicated in Table 116.
Table 116 — filesystem_­error(const string&, const path&, const path&, error_­code) effects
Expression
Value
runtime_­error​::​what()
what_­arg.c_­str()
code()
ec
path1()
Reference to stored copy of p1
path2()
Reference to stored copy of p2
const path& path1() const noexcept;
5
#
Returns: A reference to the copy of p1 stored by the constructor, or, if none, an empty path.
const path& path2() const noexcept;
6
#
Returns: A reference to the copy of p2 stored by the constructor, or, if none, an empty path.
const char* what() const noexcept override;
7
#
Returns: A string containing runtime_­error​::​what().
The exact format is unspecified.
Implementations are encouraged but not required to include path1.native_­string() if not empty, path2.native_­string() if not empty, and system_­error​::​what() strings in the returned string.