std::filesystem::path::replace_extension

Since C++17

Replaces the extension with replacement or removes it when the default value of replacement is used.

# Declarations

path& replace_extension( const path& replacement = path() );

(since C++17)

# Parameters

# Return value

*this

# Notes

The type of replacement is std::filesystem::path even though it is not intended to represent an object on the file system in order to correctly account for the filesystem character encoding.

# Example

#include <filesystem>
#include <iomanip>
#include <iostream>
#include <utility>
 
int main()
{
    const int width1{18}, width2{11}; // columns' width
 
    std::cout << std::left << std::setw(width1) << "Path:"
              << std::setw(width2) << "Ext:" << "Result:\n";
    for (const auto& [p, e] : {
            std::make_pair("/foo/bar.jpg", ".png"),
            {"/foo/bar.jpg", "png"},
            {"/foo/bar.jpg", "."},
            {"/foo/bar.jpg", ""},
            {"/foo/bar.", "png"},
            {"/foo/bar", ".png"},
            {"/foo/bar", "png"},
            {"/foo/bar", "."},
            {"/foo/bar", ""},
            {"/foo/.", ".png"},
            {"/foo/.", "png"},
            {"/foo/.", "."},
            {"/foo/.", ""},
            {"/foo/", ".png"},
            {"/foo/", "png"}})
    {
        std::filesystem::path path{p}, ext{e};
        std::cout << std::setw(width1) << path << std::setw(width2) << ext;
        path.replace_extension(ext);
        std::cout << path << '\n';
    }
}

# See also