Struct MatchArgChoicesEntry 

pub struct MatchArgChoicesEntry {
    pub placeholder: &'static str,
    pub choices: &'static [&'static str],
    pub preferred_default: &'static str,
    pub aliases_placeholder: &'static str,
    pub aliases: &'static [MatchArgAlias],
}

Entry for replacing match_arg placeholder defaults with actual choices.

Fields

placeholder: &'static str

Placeholder string in the R formal default, e.g. ".__MX_MATCH_ARG_CHOICES_mode__".

choices: &'static [&'static str]

The parameter type’s MatchArg::CHOICES, unescaped.

preferred_default: &'static str

User-supplied default = "..." value (unquoted, e.g. "zstd"), or "" if the user did not supply one. When non-empty, the write-time pass moves this choice to the front of the formal (match_arg_formal), so .miniextendr_match_arg() picks it for NULL and for the omitted argument.

aliases_placeholder: &'static str

Placeholder for the trailing aliases = (and listed =) arguments of the parameter’s .miniextendr_match_arg / .miniextendr_match_arg_several call, e.g. ".__MX_MATCH_ARG_ALIASES_run_mode__". The writer replaces , and it with match_arg_aliases_arg: nothing for a type without aliases.

aliases: &'static [MatchArgAlias]

The parameter type’s MatchArg::ALIASES, unescaped.

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 80 bytes