Question - Using subcommand multiple times with optional arguments

[lambtonr]

Hi,

I am trying to expand my CLI to allow the user to specify multiple model_ids with optional precision values (defaulted to FP16)

i am trying to do the following:

const std::map<std::string, trt::Precision> precisionmap{
  {"fp16", trt::Precision::FP16},
  {"fp32", trt::Precision::FP32}};

...

auto* model = app.add_subcommand("model", "Model params")->needs(capture);
std::string modelId {};
trt::Precision precision {trt::Precision::FP16};

model->add_option("-m,--model", modelId, "Model id")->required()->expected(-1);
model->add_option("-p,--precision", precision, "Model precision")
    ->transform(CLI::CheckedTransformer(precisionmap, CLI::ignore_case))
    ->option_text("ENUM:value in {FP16|FP32} [FP16]")
    ->default_val("FP16");

model->callback([&]() {
    std::cout << "adding model " << modelId << "with precision " << (precision == trt::Precision::FP16 ? "FP16" : "FP32") << std::endl;
    pipeline.model.emplace_back(ModelConfig{modelId, precision});
  });

what i am trying to achieve is is the following functionality

./app model -m model_id_1 -p FP32 model -m model_id_2 model -m model_id_3 -p FP32
or 
./app model -m model_id_1 -p FP32 -m model_id_2 -m model_id_3 -p FP32

I can get it working if i use a vectorstd::string id, vectortrt::Presision precision and make them both required but allowing the precision as optional misaligns the two vectors.

Many Thanks

[phlptp]

Would it be an option to not have the -p part and just have it be -m model_id_1 FP32 -m model_id2 -m model_id3 FP16 Then having them stored to a vector of pairs? If that is an option there are ways of specifying the defaults and keeping things aligned?