Std::experimental::filesystem::path::compare (3) Linux Manual Page

std::experimental::filesystem::path::compare – std::experimental::filesystem::path::compare

Synopsis

int compare(const path &p) const;
(1)(filesystem TS)

    int compare(const string_type &str) const;
(2)(filesystem TS)

    int compare(const value_type *s) const;
(3)(filesystem TS)

Compares the lexical representations of the path and another path.
1) Returns a value less than, equal to or greater than 0 if the native representation of the path (native()) is respectively lexicographically less than, equal to or greater than the native representation of p (p.native()). Comparison is performed element-wise, as if by iterating both paths from begin() to end().
2) Equivalent to compare(path(str)).
3) Equivalent to compare(path(s)).

Parameters

p – a path to compare to
str – a string representing path to compare to
s – a null-terminated string representing path to compare to

Return value

A value less than 0 if the path is lexicographically less than the given path.
A value equal to 0 if the path is lexicographically equal to the given path.
A value greater than 0 if the path is lexicographically greater than the given path.

Exceptions

1)
noexcept specification:
noexcept
2-3) (none)

Notes

For two-way comparisons, binary_operators may be more suitable.

Example

// Run this code

#include <iostream>

#include <experimental/filesystem>

namespace fs = std::experimental::filesystem;

void demo(int rc, fs::path p1, fs::path p2)
{
    if (rc < 0)
        std::cout << p1 << " < " << p2 << '\n';
    else if (rc > 0)
        std::cout << p1 << " > " << p2 << '\n';
    else if (rc == 0)
        std::cout << p1 << "==" << p2 << '\n';
}

int main()
{
    fs::path p1 = "/a/b/"; // as if "a/b/." for lexicographical iteration
    fs::path p2 = "/a/b/#";
    demo(p1.compare(p2), p1, p2);
    demo(p1.compare("a/b/_"), p1, "a/b/_");
}

Output:

"/a/b/" > "/a/b/#"
"/a/b/" < "a/b/_"

std::experimental::filesystem::path::compare (3) Linux Manual Page