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

From cppreference.com
< cpp‎ | experimental‎ | fs‎ | path
 
 
Technical specifications
Filesystem library (filesystem TS)
Library fundamentals (library fundamentals TS)
Library fundamentals 2 (library fundamentals TS v2)
Library fundamentals 3 (library fundamentals TS v3)
Extensions for parallelism (parallelism TS)
Extensions for parallelism 2 (parallelism TS v2)
Extensions for concurrency (concurrency TS)
Concepts (concepts TS)
Ranges (ranges TS)
Mathematical special functions (special functions TR)
 
 
 
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)).

Contents

[edit] 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

[edit] 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.

[edit] Exceptions

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

[edit] Notes

For two-way comparisons, binary operators may be more suitable.

[edit] Example

#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/_"

[edit] See also

lexicographically compares two paths
(function) [edit]