getter for registeredParams_?

[paleozogt]

After calling add_param(s) I'd like to be able to read them back out. Can we add a registered params getter? For example:

std::set<std::string> const& registered_params() const { return registeredParams_; }

This would allow us to write our own "--help" flag handling:

argh::parser cmdl(argc, argv, argh::parser::PREFER_PARAM_FOR_UNREG_OPTION);

cmdl.add_param("a");
cmdl.add_param("b");
cmdl.add_param("c");
cmdl.add_param("help");

if (cmdl.params().empty() || cmdl["help"]) {
    cout << "Help:\n";
    for (auto &param : cmdl.registered_params()) {
        cout << "--" << param << std::endl;
    }
    return 0;
}

[helmesjo]

IMO --help & -h should be built-in and handled automatically. A cli tool without a help print shouldn't be allowed. ;)

[adishavit]

@paleozogt: I somehow missed this issue when you posted.
That’s easy to add but I’m not sure I see the benefit. Since there is no support for help strings / usage, you’d have to write your own usage anyway, and only you know the supported options.
Argh kinda encourages you to be lazy and not preregister. Besides you’d still have to specify the flag arguments “manually”.

A future C++20 version will support automatic usage info, but that’s still a while away.

[ljluestc]

#include <iostream>
#include <set>
#include <string>
#include <argh.h>

int main(int argc, char* argv[]) {
    argh::parser cmdl(argc, argv, argh::parser::PREFER_PARAM_FOR_UNREG_OPTION);

    // Define a set to store registered parameters
    std::set<std::string> registeredParams;

    // Define and register parameters
    cmdl.add_param("a");
    cmdl.add_param("b");
    cmdl.add_param("c");
    cmdl.add_param("help");
    
    // Store registered parameters in the set
    for (const auto& param : cmdl.params()) {
        registeredParams.insert(param);
    }

    if (cmdl.params().empty() || cmdl["help"]) {
        std::cout << "Help:\n";
        for (const auto& param : registeredParams) {
            std::cout << "--" << param << std::endl;
        }
        return 0;
    }

    // Other command-line processing logic here...

    return 0;
}