Args::Flag: Add required attribute
#14087
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| if (flag->required && flag->timesUsed == 0) | ||
| throw UsageError("required argument '--%s' is missing", name); |
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Can we list multiple such flags?
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Yes, there can be multiple required flags.
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Yeah I mean collect them all and throw error with all of them
Ericson2314
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| // FIXME: this should be private, but that breaks designated initializers. | ||
| size_t timesUsed = 0; |
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It's really ugly that Flag becomes mutable. Can we avoid this by storing the use-count separately? I would hope that Flag stays an immutable description with a callback. Can't we instead track if the argument has been specified multiple times in the Handler?
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Yes I would prefer that too, thanks for catching @xokdvium
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I don't think it's a problem since Args owns the Flags anyway (i.e. it was already mutable).
Motivation
This allows specifying flags that are mandatory. The motivation was
nix nario export(#13969), which has a required--formatflag.Note: The
timesUsedcounter could also be used to warn about flags being set multiple times (#13899).Context
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